Thursday 1 May
1) Don't forget the hardcopy of your test answers is due on Monday 5 May. I will grade it up and get back to each of you re: grades and such.
2) Our last 5 presentations occur on Monday - and then ...freedom, from me!
During lecture we focused upon ethanol and issues surrounding the production of and possible aid for a hangover.
We began by differentiating between ethanol (ethyl alcohol, grain alcohol) and methanol (methyl alcohol, wood alcohol).
Ethanol is the active ingredient, the drug if you will, found in liquor, beer and wine - essentially any alcoholic potent potable .
Methanol is wood alcohol and its consumption can lead to the destruction of the myelin sheathing of the optic nerve, and thus, blindness.
This led to a quick discussion of terms which seem to be unfamiliar to the class - but ones I think you may still hear from time to time ... such as; blind drunk, bathtub gin, moonshiner etc. Then again, perhaps you will never hear these terms - I am of a certain age ....
After a quick review of the organic, molecular and covalent bonding of ethanol we looked at the 4 Horsemen of the oncoming hangover:
1) The prevention of vasopressin (anti-diuretic hormone ADH) to release water back into the body. Hence, dehydration occurs.
2) The conversion to and subsequent buildup of a toxin called acetylaldehyde.
3) The glutamin rebound
4) Congeners
In short, drinking shuts off our supply of vasopressin (ADH) and we dehydrate. Body organs pull water from our spongy brain, and our brain shrinks in volume, pulling on membranes holding it in our skull. This causes pain and a great deal of the morning - after headache.
Ethanol is oxidized to acetylaldehyde - a nasty toxin with the seeming ability to interfer with everything from mitochondrial function to enzyme activity.
Now, our live contains a small supply of glutathione - the KING OF ANTIOXIDANTS ... a magical compound, with the ability to turn the toxic acetylaldehyde to acetic (ethanoic) acid and shunt it out of the body.
However, the supply of glutathione is very small - and it takes time to reconstitute our reserves. Hence, anything we can do to help resupply it - is a good thing. Glutathione is a pretty standard organic molecule, with C, H, O, a little N and oddly, Sulfur (S). Hence, the key is to get sufficient sulfur to help rebuild our depleted supply of glutathione. Hard boiled eggs with their rich supply of a sulfur-containing amino acid called cystiene can do the trick - per the rumors. The best case is to avoid excessive drinking all around!
While ethanol affects an inhibitory neurotransmitter, referred to as GABA, and thus weakens our muscular control, speech etc, we also fail to supply sufficient glutamine (an excitatory neurotranmitter).
Sometime during sleep - as the alcohol is oxidized away, the glutamine rebound occurs - causing anxiety, stimulation, lack of sleep etc - adding to the woes.
The confusing critters, congeners are the last aspect. Congeners are "born with" (as in the medical term, congenital) the fermentation of alcohol - especially the dark liquors.
Some congeners help ease the natural bleeding of the stomach with the consumption of alcohol - while others may be mild toxins. They are a mixed bag.
Don't over imbibe . Always have a ride - or better yet, keep to soda and be someone else's ride.
Okay - write with questions ... See you Monday for a little nutrition and the evals.
Monday 28 April
Assignment:
1) Your last test (there is no Final exam during exam week), was given out . A hard copy of your responses is due on Monday 5 May. If you didn't get a copy - please email me. I will email everyone with results and grades. Be sure to word-process (type) out your responses. And, yes, it is missed numbered. There are only 11 questions - but because I tossed question 10 and never renumbered, the numbering is off. Don't sweat it ... just be sure I know what you're answering.
We began where we left off with vaping. And I think I have abandoned all pretense of neutrality on the issue. This stuff is simply a trifecta of bad.
The three issues surround that :
1) the nicotine content. Nicotine is an alkaloid and natural pesticide (for the tobacco plant) and variations (derivatives) are used heavily in agriculture.
While the use of nicotine itself as a pesticide has decreased derivatives made from nicotine, called neonicotinoids are used instead.
I re-emphasized the interpretation of a skeletal formula, using diagrams of nicotine as an example. Don't let those diagrams freak you out. Every carbon requires 4 covalent bonds and at every vertex of a diagram (like nicotine or benzene) there is a carbon and possibly up to two hydrogen, unless otherwise indicated.
2) The nicotine is soluized (dissolved) in a an oil carrier. This fairly homogeneous mixture is heated, vaporized and carried into the lungs via inhalation. Oil in our moist, thin respiratory system, does not belong. Oil and water do not dissovle into each other. This build up of oil is believed to compromise efficient gas exchange between the blood and gases of the lung.
3) The metal coild is heated ( by a battery) and over time the metal can corrode (or become oxidized). This means that the nickel or chromium in the coil can lose electrons to oxygen. These ions can be swept up into the inhaled stream of the vape. These ions can be carried into the lungs - and the various ions have carcinogenic potentiality.
With that done we moved onto a look at a number of compounds which use petroleum - derived benzene as a building block. This led us to a few poor jokes and ultimately a look at the function of analgesics (pain reducers) such as the NSAIDs and Tylenol (which is not an NSAID as it lacks the ability to deal with inflammation.)
We also took a look at folate and folic acid . Folate is the naturally occurring form of Vitamin B9 while folic acid is the synthetic form. The CDC has a very interesting video regarding the fortification of fooeds with folate.
It's really pretty good - and worth the 6 minutes or so - just to educate yourself.
Check out: www.cdc.gov/folic-acid/about/index.html
Scroll down about 2/3 of the page and you will see the video. I can't seem to find this exact video on YouTube, so I am providing it here in a slightly clunkier manner.
Okay, that's about it. Write with questions - I will see you Thursday and we will attack alcohol and hangover.
Thursday 24 April
We wrapped up Unit 2 as we finished a look at Climate Change. I chose not to push us into the more complex rationale for climate change (e.g. I chose not to go into stratospheric cooling) - as I felt time was getting short.
On the board I developed a few statements that should have encapsulated prior work:
1) Visible light (ROYGBV) from sunlight passes through the atmosphere.
Yes, per our video on radiative balance, some sunlight is reflected back to space & per our conversation re: ozone, UV rays are stopped to some extent & blue wavelengths tend to undergo Raliegh scattering ... giving us a blue sky.
The takehome message is that our atmosphere is like glass when it comes to visible light. Much of the visible light from the Sun passes right through our atmosphere.
2) Sunlight (ROYGBV) strikes Earth's surface and it is converted to infrared energy ("heat").
So this point is important as it demonstrates, again, that energy can be converted from one form to another and/or transferred.
In this case, a form of kinetic energy (eg electromagnetic spectrum) is converted to infrared energy (another but different form of electromagnetic energy [eg kinetic energy].)
You know the term, heat, is misused here as the term is not identical in meaning to infrared energy. Rather the term, heat, refers to the process of transferring energy - but I am not going to win the battle of parsing the difference between the terms. Hence, infrared energy can be interpreted as "heat energy" for our purposes.
3) The surface of the Earth radiates (releases) "heat energy" into the atmosphere.
So to recap: Visible light strikes, is converted to heat and in turn that heat is released back into the atmosphere.
4) Infrared Active (IA) molecules are in the atmosphere (CO2, H2O, CH4). These IA molecules absorb the radiating "heat energy" (infrared energy) .
The kinetic infrared energy is converted to POTENTIAL ENERGY as the electrons of the bonds making up the IA molecules stretch, wiggle, bend. BUT THE BONDS DO NOT BREAK!
The bonds return to a more natural length, reducing their POTENTIAL ENERGY and having it CONVERTED BACK to kinetic energy (which really is just infrared energy.)
The bonds do not break hence, a cycle of absorption of heat energy and the subsequent release of heat energy back into the atmosphere , is established.
In short, this is the (misnamed) Greenhouse Effect. ( This is isn't how a greenhouse works - but I need to use the terms I am given.)
The Greenhouse Effect is a good thing - in that it warms the Earth and helps to allow life to flourish.
However, too much of a good thing is the problem.
The burning of fossil fuels deposits more and more IA molecules of carbon dioxide into the atmosphere. The presence of these molecules "trap and release" more and more heat energy in /into the atmosphere.
In turn, this increase in atmospheric temperature warms the waters of the Earth, increasing the rate of evaporation, depositing even more humidity made of IA molecules of water vapor!
As the atmosphere warms wind speeds can increase. Water temperatures can increase. Storms such as hurricanes form over water. The warm water heats these storms, increasing wind speeds even more, creating this monster storms.
The warming of the Arctic has destabilized / weakened the form of the Jet Stream. As the Jet Stream weakens colder Arctic air descends southwardly towards areas, like CT. This affects our winter months.
As the Earth warms, glaciers on Antarctica and Greenland melt, sending huge amounts of water into the oceans. Ocean levels may rise, in time, by 20 to 30 feet. The obvious impact on low lying coastal areas is obvious.
As the Earth heats, new deserts may form, impacting farmland/grazing land and thus disrupt food production. The wheat belt and corn belt of the USA may move northwardly towards Canada.
The increase in ocean temperatures has begun to affect the reproductive patterns of fishes and other marine life. This too will create disruption to food production / acquisition.
In all probability, it is projected that the Earth shall not heat uniformily as our climate changes over the next number of generations. New patterns will emerge. What remains / changes is not clear in my crystal ball.
Governments have considered using satellite - based mirrors to reflect sunlight away from the Earth, so as to help cool it. Scientists have considered the effects of seeding the sky to increase cloud cover so as to increase the albedo (the ability to reflect light) of the Earth.
We then began the new set of notes with a look at nicotine.
I introduced the terms, ALKALOID. An alkaloid is a plant-derived nitrogen containing organic molecular compound (ooh the terms!!!!) that can have a physiological effect on our biochemistry (good and bad
Nicotine (tobacco), caffiene (cocoa, tea plant, coffee), morphine (poppy), strychnine (seeds of the nux vomica tree), atropine (deadly nightshade) are examples of alkaloids.
We pick it up on Monday! Okay, write with questions!
Monday 21 April
Okay! We are just about done with this unit. On Thursday we shall wrap up climate change and move onto some mini-topics.
In this latter section on energy I have been trying to provide you with a number of applications as to how energy is transferred from source to sink/chemcial and/or converted into other forms.
For instance we now know that the Sun's visible light energy is the energy which penetrates our atmosphere and is converted into infrared energy.
The energies upon which I have been most focused are the various forms of the electromagnetic spectrum.
It is in this topic that I have been trying to marry ideas of electron activity, to bonding to infrared reactivity, to potential and kinetic energy.
What follows are a number of the take aways from this section.
1) Electromagnetic spectrum energy is due to the changes in energy of electrons as they move from higher levels of energy to lower (or more natural) levels of energy.
2) The form of energy released by chemical species due to these electron transitions depends upon the extent of that transition. The type of energy that is released is dependent upon the electron transition. Not all transitions are equal.
3) We can identify the energy released by the wavelength and frequency. Recall that the wavelength and frequency are inverses of each other - in that the greater the wavelength, the smaller the frequency.
4) While all electromagnetic energy travels at the speed of light (in a vacuum) , they may deliver differing amounts of energy due to differences in their frequencies.
5) Visible light can be divided into multiple wavelengths known as ROYGBV. Per our discussion of visible light, red wavelengths tend to have the longest wavelengths, thus the smallest frequencies. Violet wavelengths tend to be the smallest wavelengths and thus the greatest frequencies.
We also know from the SciShow video that sunlight is not uniform. It leans heavily towards the green frequencies. This fact may have influenced the evolution of green plants - in that green plants do not absorb much green light at all. Rather, the color we see is due to the rejection or failure to be absorbed by the electrons of the molecular compounds of the plant.
6) Our demonstration of the effects of visible light upon the precipitate AgCl demonstrated that visible light may indeed affect bonds, do work/create a change upon chemical substances. As we proved, the blue wavelengths had the ability to break the ionic bond of solid AgCl, decomposing the compound into solid silver (the black/gray specks) and chlorine gas.
7) Silver chloride hence is sensitive to various wavelengths of light. Silver chloride was/is used in old timey black and white photography. Due to its low frequency, and inability to affect photographic chemicals, red light is used in photographic dark rooms.
8) This sensitivity of bonds to various forms of electromagnetic spectrum energyies was seen again, as we learned about UVA and UVB light having sufficient energy to disrupt the bonds found in molecules of our skin.
9) This sensitivity was seen again, as we looked as x-ray energy being able to disrupt the bonds in DNA.
10) This ability to be absorbed/released or to disrupt bonds was seen in our study as to why the sky is blue. Atmospheric chemicals can absorb and release (without bond disruption), blue light. This is due primarily to the nitrogen in our atmosphere.
11) Lastly this theme of electromagnetic energy was seen again as we began our work on climate change. Certain molecular chemicals in our atmosphere have the ability to absorb infrared energy coming off of the Earth's surface.
These infrared active molecules include carbon dioxide, methane and water vapor. Gas molecules such as oxygen and nitrogen are far more sensitive to ultraviolet light and do NOT have a significant impact on what we term, the Greenhouse Effect.
In short, the electrons of the bonds found in infrared active molecules can absorb infrared energy coming from the surface of the Earth WITHOUT breakage to the bonds. These bonds undergo an increase in potential energy, and a resulting decrease in potential energy, by converting the absorbed electromagnetic energy back into infrared (electromagenetic or kinetic) energy frequencies.
This capture and release of infrared energy is the founfsdation of the process of the Greenhouse Effect, the process by which the young Earth began to warm .
Okay! We finish on Thursday .... Write with anything you wish!
Monday 14 April
(My apologies folks - this blog was not published (by me) when I wrote it. I must have closed down after writing it and never hit publish.
We are up to page 60 of the note packet.
Tonight was all about the electromagnetic spectrum - those energies released and associated with the movement of electrons as they move from a higher (excited) energy to a lower (natural) position outside and relative to the nucleus.
We spent a fair amount of time discussing the inverse releationship between wavelength and frequency.
The larger the wavelength - the smaller the frequency.
The smaller the wavelength - the greater the frequency.
The above relationship can be applied to explaining the high energy delivery of EMS energy in the form of ultraviolet rays, x-rays and gamma rays.
We watched the steel ball hit an anvil video (the link is in your notes) to try to drive home the relationship between wavelength and frequency.
We then moved back to the to look at the various forms of "light". I got off on a rant regarding bees and birds and polarized light.
ROYGBV helps to recall the wavelengths of visible light, with violet being associated with the smallest wavelength and greatest frequency of visible light.
Beyond violet is ULTRAviolet. The prefix ultra means , beyond to to the extreme of....
Ultraviolet rays (those absorbed during sun-tanning) have the energy (the ability to do work/create change) beneath the outer layer of skin.
UV B rays tend to penetrate to the lowest layer of the epidermis. Now, the epidermis is the outer layer of skin - but it is further divided up into "sub layers". UV B rays can penetrate down to the basal layer and create what you and I call sunburn, via the endothermic destruction of bonds.
UV A can penetrate deeper - beneath the epidermis and disrupt the cells of the dermis. UV A contributes to the destabalization of collagen and elastin. Translation .... UV A contributes to wrinkles and an aged look to the skin.
Recall collagen is the protein with a dependence upon Vitamin C, as the vitamin helps to deposit and convert hydroxyproline in the production of collagen.
UV A is also the culprit regarding skin cancer.
Now, I am not a dermatologist - but this is your professor's suggestion that you to speak to a professional (your GP or a dermatologist ) and get their opinions regarding the use of a good suncreen . Many suncreens are incorporated right into moisturizers and you know I have pitched the idea of moisturizers in the past ... But you speak to your doctor.
We then moved onto the idea of color and from whence color comes. We will also see on Thursday why plants tend to be green.
Okay - write with questions. Papers are due. See you soon.
Thursday 10 April
Assignments:
1) Thursday, April 17th your final papers are due!!!
This is a quick blog to write ... as we wrapped and reviewed a couple of concepts - and then began our work on the electromagnetic spectrum.
We are on page 58 of the notes.
We wrapped up work on exothermic/endothemic energy exchanges. I also worked to put in context a review on ground state electron configuration and excited state configuration.
Excited state configuration is important in that it ties together ideas such as:
1) potential energy can increase and decrease (via a conversion to some form of kinetic energy)
This idea involves:
2) as electrons move further from the nucleus, due to an absorption of energy, they occuy a higher level of energy.
3) the attraction of the nucleus for that electron still exists and that electron will return to its original position by losing potential energy. However, (and this is the learning), that lost potential energy is converted into kinetic energy, such as light or radio waves, or microwaves. This obeys Big Idea #1 The Law of the Conservation of Matter, Energy and Charge . Energy cannot be created or destroyed by ordinary chemical means - but that energy can be converted into other forms and/or transferred.
4) Hence, as an excieted electron moves from a higher energy level to a lower energy level, it releases energy along the lines of electromagnetic spectral energy... visible light, infrared, radio wave, x-rays, microwaves, ultraviolet waves
5) The forms of electromagnetic spectral energy are related to each other because they are each due to the motion of excited electrons dropping from higher to lower energy levels.
6) The range or extent of positional change dictates the type of electromagnetic spectal energy released.
The YouTube video I used to describe the above phenomena is not in your notes. However, I am linking the video (click here). We began around 10 minutes 30 seconds in the video and ended around 20 minutes into the video.
Armed with the visuals from this video we could link electron configuration, valence electrons, excited electrons, and the electromagnetic spectrum.
The discussion then shifted to the wavelength and frequency of electromagnetic energy.
All electromagnetic energy travels at the speed of light, (around 3 x 10^8 meters/second) in a vacuum.
So radio waves travel as fast as visible light waves in a vacuum.
The difference between the various forms of electromagnetic energy are those wavelengths, and frequencies.
And, as demonstrated in class - they are inversely related. This means that the smaller the wavelength, the greater the frequency. (More on this on Monday).
Radio waves have a large wavelength (like the size of a football field), whereas visible light waves have a wavelength around the size of a bacterium.
We can deduce then that radio waves have low frequencies and visible light has much higher frequencies.
These ideas were applied to why we needed to be careful as to how many x-rays we get taken per year.
X-rays have very small wavelengths thus they have an incredibly high frequency and can deliver a great deal more energy to a system in the same period of time as a radio wave.
Okay - that's it! Everyone should be working on their final papers. Those are due Thursday - 17 April!!
Write with questions.
Monday 7 April:
I
Assignment:
1) Your take home test is due on Thursday. If you are absent on Thursday, you need to scan or photograph you answer sheet and send it to me via email that night. That stops the clock and you can turn in your test the next time we meet. Be sure to "X" your answers. Read the directions!!!!!
I reinforced that you will see issues, surrounding exothermic and endothermic energy exchanges on your next test. I think it is fair to say, perspiration and climate change and reactions in beakers (like our practice problems) would be on that exam.
I felt last night was a big night for us - what with the problem set and the lab. I am linking a copy of the lab worksheet (click here). It has the orignial 4 reactions - BUT!!! I am including an answer sheet which also has that first demonstration of rusting iron I worked through with you on the board AND I have provided a "key" to the identification factors for the terms at the bottom of the answer page.
That worksheet is your lab write-up. So if you were there you earned 25 points.
Focus on your take home (one more to go) & writing your paper. Check those due dates in the Introductory Packet. Okay?
We are up to page 51 of the note packet.
We worked through the benefits of a Frayer Diagram. I urge you to consider creating some of your own.
We then went into the problem set. This stuff is not so obvious - however, I think through your continued questioning, I think we summed things up nicely.
Consider using this:
When the energy exchange is:
exothermic: as products are made, chemicals lose energy and the environment heats up.
endothermic: as products are made, chemicals gain energy and the environment cools down.
This works for chemical reactions and/or physical changes! Go back and look at the problem set ... try the questions without looking at your answers and see it the above helps. If not, drop me a line.
We then drew the link between the average kinetic energy and temperature. THEY MEAN THE SAME THING.
I explained why temperature is the measure of the average kinetic and not the system's entire kinetic energy - with my magnificient drawing of a thermometer in my giant beaker of science (say that with an echo)!
Recall that only an average number of molecules in the systemt interact with the temperature bulb .
We emphasized that energy moves from high to low (an that transfer is referred to as "heat")
We also reemphasized that there is no such thing as cold energy. "COLD" is simply the lack of thermal energy.
Okay, write with concerns/questions ... I keep checking to see if you wrote! I will get back to you ASAP.
Thursday 3 April:
This lecture focused upon endothermic and exothermic energy exchanges - and as these terms apply to chemical reactions and physical changes.
First - under natural circumstances, energy flows from high(er) levels to low(er) levels of energy.
Bond breaking absorbs energy and bond making releases energy.
We took another look at applicable potential energy diagrams. Such diagrams are pretty sophisticated - being used in any unit on kinetics (the rate of a reaction).
With that we worked through a number of applications and how we can analyze the energy exchanges in these applications.
I think one of the harder pieces to master deals with physical changes. We must constantly analyze what must be done to the reactant to get to the product when dealing with physical changes.
Thus, we can think about boiling water. Yes, boiled water is hot ... but the question must become what needs to happen to liquid water in order to produce boiled (or vaporizing water).
The answer is we must ADD heat to liquid water. This means that the physical change is best classified as an endothermic energy exchange.
We covered the phenomenon of the sweating glass, air conditioners, freezers, refridgerators.
The most complicated application was a look at the process of perspiration.
First, we must look at perspiration as "dirty" water. And, like any aqueous mixture, the molecules are relatively close to each other (when compared to the vaporized form).
Secondly, we must keep uppermost in our minds that due to our relatively high body temperature (97.4F) we are often the hottest thing in the room.
Thirdly, we are homeothermic organisms (some of us might say, "warm-blooded"). This means that we maintain a relatively constant internal temperature - regulated via various mechanisms.
One such mechanism is perspiring.
Water is released onto our skin - and we - acting as "the stove" heat that water. (Energy moves from high to low).
As that water heats, it turns into a gas - a gas with a greater potential energy. That means that there is a conversion of kinetic (thermal energy) to potential energy. That kinetic or thermal energy is the excess energy building up inside our body. In order to maintain an appropriate internal temperature that excess energy must be lost.
Thus, as our sweat turns to vapor, the heat, from our body is transferred into the perspiration and leaves our body as the vapor dissolves into the air! Viola! We - cool down.
Write me with your thoughts and/or concerns. Enjoy your weekend.
Monday 31 March:
I am quite late - I know - and for those last minute reviewers I am pushing through to post. Time has simply been eaten up by unexpected business.
Assignment:
1) For your Candle Lab Report you need only complete questions 4, 5, 8 (and the objective ...reflection etc). They are in boldface on the last page of the prelab/lab handout.
2) Don't forget your take home is due on Thursday 10 April. You need to "X" your answers. Do NOT just circle answers - if you are someone who circles. You need to "X" per my explanation and directions.
Well I know the change in season is bringing on some tiredness - and I feel for you folks. Work to stay with me in lecture as we are at some of the more interconnecting ideas by now. Frankly, I think you did really well on Monday - tired - but involved, focused.
We made it to page 41 of the notes - but we did a whole lot of chemistry!
I have been focusing upon bonds as of late. These chemical unions between chemical species that represent some level of potential energy.
When a bond is broken, energy must be absorbed, as the bond represents an energy which must be overcome.
The energy absorbed during a period o bond breaking is often represented as ACTIVATION ENERGY. Thus bond breaking is an ENDOTHERMIC process, meaning that more energy must be absorbed.
The source of the energy is most likely from the environment (the air , the water surrounding the reacting chemicals , a Bunsen burner, stove etc....)
When a bond is made, energy must be released -as the the position, the potential energy between the reacting species decreases.
Bond making doesn't have a special name - but it must be an EXOTHERMIC process. More energy is relelased.
When more energy is released than is absorbed - we term the overall reaction to be exothermic.
Now this is a touch confusing - as me must always consider the issue of overall exothermic or endothermic from the point of view of the chemicals - not the environment.
We must consistently ask ourselves what or where is the actual reaction occurring.
During an exothermic CHEMICAL reaction, energy is released into the environment of the air or water. That means the surrounding air or water become(s) warmer.
When more energy is absorbed during bond breaking than is released during bond making, we term the overall reaction to be endothermic!
During an endothermic CHEMICAL reaction, energy is absorbed by the chemicals FROM the environment. Hence, the environment suffers a cooling effect, as energy is drawn out of the environment.
For physical changes we must analyze slightly differently.
Okay - We hit the road tonight running. Write with questions.
Thursday 27 March:
Well, I am a bit later than usual in posting - it has been a busy weekend - but it's Sunday morning and I am ready to go.
Assignments:
1) Poylmer lab report is due on Monday. Be very sure you follow the directives.
2) Your topics for your term paper are due by Monday, 31 March. It is graded . Be aware that I shall not hesitate to tell you that you have gone astray - after your paper is written - if I did not "okay" the topic.
3) We will do the Candle Lab on Monday night. The pre-lab is posted under the Notes tab on this website , and I will have a hard copy for you on Monday.
We are kneedeep into our work on Energy. We are at the top of page 39 in the newest notes packet.
Essentially I am working to draw a line between the concept of potential energy (Big Idea #3) and chemical bond energy.
Potential energy increases with an increase in distance between two chemical species and potential energy is lesser as that distance is decreased.
Whenever a bond is made, energy is released. In order to bond, two species must get closer together.
As a covalent bond is formed, the positive nucleus of one atom attracts the electrons of a second atom. And, the electrons of the first atom are attracted to the positive nucleus of the second atom.
A potential energy exists between the two species. As the bonding process occurs (like shaking hands), the two species must move closer to each other.
As they move closer to each other, the position decreases (This means the potential energy must also decrease).
However, we know from Big Idea #1 that energy is conserved. That decrease in potential energy cannot just disappear.
In fact, that potential energy is CONVERTED to a kinetic energy (in the case of bonding it is often thermal or infrared energy).
This infrared energy is released into the surrounding envirnonment.
Hence bond making releases energy.
The resulting bond does, however, continue to represent a particular amount of potential energy as the bond has a length and a strength.
Short bonds tend to be quite low in potential energy and conversely short bonds tend to be quite strong.
Because the potential energy is so low, it takes a greater input of energy into breaking it - hence a shorter bond tends to be stronger.
Bond breaking absorbs energy - and we will investigate more of that on Monday.
Okay! I think that's it. Write with questions / concerns. I will get back to you ASAP!!!!
Monday 24 March:
Assignments:
1) Your polymer lab report is really a mini-paper. The requirements are listed on the last page of the pre-lab you picked up in lab. If you have lost your copy, you can download or review the work using the link found on the "Notes" tab of this website. You do not need an objective or a reflection. You do need to embed your citations and a works cited. A single page of type at Times New Roman 12 font, should have around 22 to 25 lines of type. (My head is full of stuff you cannot even begin to imagine.)
2) (This isn't really an assignment - just an FYI.) We will perform the candle lab next Monday - not the food chemistry lab. I will give you a copy of the lab in class on Thursday.
Okay, everyone picked up a copy of the notes for the newest unit - Energy!
Here's a re-cap of what I think was a productive evening's work.
Energy is all about the ability to create a change (or to do work).
Two major forms of mechanical energy are potential energy (chemical bond energy is a form of potential energy), and the more familiar kinetic energy (light, microwaves, radiowaves, running, moving, infrared, ultraviolet, singing, sound....)
To help explain the ability to create a change or to do work, I began to discuss muscle contraction. Myosin and actin protein fibers found bundled in sacromeres can slide over each other (there's change in position ) .
We then began to discuss the tiny but effective Ca^+2 bridges between the fibers and the need for K^+1 for the release of the contracted muscle fibers.
All was well and good - and THEN ... and THEN there was that question about grape seed oil - which led to Resveratrol, and its classification of an antioxidant. Hey Tom, what's an antioxidant? .... Oh Goodness.... Grape seed became a wonderful seed for the next 40 minutes of class! (Did you "seed" what I did there?)
I began to discuss the oxidation of Mg in a reaction of O2(g) to produce MgO(s).
Then I heard the crickets chirpping. I became convinced folks were not with me - so I determined that we needed to punt ...
We began with a review of electron configuration. Using the less-than - perfect Bohr model (but appropriate for our purposes), I reviewed that electrons can be organized around the nucleus of an atom, at points of energy possession or quanta.
It is pretty common to state that as a rule, the first level can hold a maximum of 2 e-.
The second level can hold a maximum of 8 e- and so on, per a calculation of 2n^2 where n is the number of the energy level.
So, assuming the 1st energy level, 2(1)^2 equals 2. Hence the max number of electrons is 2.
For the second level 2 (2)^2 equals 8. Hence the max number of electrons is 8.
The other rule to consider is the Octet Rule (or rather the Octet Reasonable Guideline of Sorts). This establishes that the outer most layer of electrons (1 to 7) most probably holds a maximum of 8 electrons.
That is, the outermost energy level of an atom will probably hold 1 to 8 valence electrons. And, as a generally reasonable guideline we can state that atoms tend to react so as to acheive 8 valence electrons or as close to 8 as is possible.
This idea led us to master (and you folks absolutely did master this) the prediction as to whether an atom would lose or gain or share electrons in order to gain stability.
When an atom has fewer than 4 valence electrons it will probably lose those valence electrons and drop back to a completed energy shell.
The atom will become OXIDIZED.
When an atom has more than 4 (as in 5, 6, 7 valence electrons), it will probably gain enough electrons to get to 8.
The atom will become REDUCED.
You see, very often, atoms give up charge neutrality (a charge of 0 when #p = # e-), in order to get to 8 valence electrons.
Atoms will turn into IONS.
This often confers a chemical stability. Chemical stability generally refers to a the unlikelihood that the species will react again.
Na^+1 ion is a very stable chemical species.
O^-2 ion, the oxide ion is a very stable chemical species.
The Noble Gases (except for He) are species which already have 8 valence electrons - Thus, noble gas species tend NOT to make chemical bonds by losing, gaining or sharing electrons. They already have the perfect situation, as it were.
Thus, there is no such compound here on Earth as NeO [neon oxide] as neon does not make bonds and is not found in compounds!
Once we had that down, and with the introduction of LEO says GER (or OIL RIG), we took another run at the chemical reaction between Mg and O2.
I identified Mg as the oxidized species and the atoms of oxygen in O2 as the reduced species.
I then introduced that another term for the reduced species was OXIDANT.
Hence, OXIDANTS are reduced. (Oxidants gain electrons.)
An ANTI-oxidant must thus be the oxidized species.
This applies to resveratrol, and to some extent Vitamin C (but poorly), or curcumin (from tumeric) or anthocyanins (from blueberries), or Co-Q 10, selenium, or betacarotene, or catechins (from green tea) or
glutathione, or lycopene (from tomatoes) or flavanoids (from dark chocolate) ....in that these are all relatively good antioxidants.
These compounds lose electrons to ROS (reactive oxygen species such as O^-1). They become oxidized and in doing so, they protect our proteins, fats, and DNA from the attack of ROS.
Hence, diets high in antioxidants tend to help slow the negative effects of aging. Antioxidants in our diets help to preserve and to protect our vital structural and functional materials from the attack of radicals!!!!!
We didn't get very far with energy - but dang(!) we did a great deal of chemistry!
Be proud of yourselves. Brava! Bravo! A round of applause to each of you.
See you Thursday! Write with any questions / comments / concerns ...
Thursday 13 March:
Assignments:
1) I will be posting midterm grades. Should you have questions, be sure to drop me an email.
2) Read your polymer lab!!!! Be ready for that lab when we return.
We have finished the first note packet ... getting all the way to page 36. Next time we meet we shall begin our work on energy and a little bit more of atomic structure.
Our work encapsulating intensive/extensive properties of matter (in general) -especially - specific heat, and those energy exchange processes (like how a pond freezes) will be on our next test.
Thus, take a few moments to get the notes, to read over the remainder of the packet and/or get in touch with me to discuss issues should you wish to do so!
Okay - per the notes, extensive properties change as the amount of material changes. Mass , volume and the number of molecules are extensive properities ... add more matter, mass changes, volume changes, the number of molecules changes.
Intensive properties can be interpreted essentially as constants - they are properties that do NOT depend upon the amount of matter.
Assuming constant pressure and temperature, intensive properties include melting point, density , a nd normal boiling point. These intensive properties are perfect for helping to identify the compound or element.
Specific heat is the intensive property upon which I chose to focus.
Specific heat is a value which indicates the amount of energy (Joules), required for 1.00 gram of matter to change temperature by 1 degree Celsius (for our work).
For our class, we can stand by the statement : Slow to heat up, slow to cool down and Fast to heat up, fast to cool down.
This surrounds ideas such as lake effect snow, why the swimming pool water is so cold in the morning but so warm at the evening (we did this during a demo of boinling water), aluminum foil's use in cooking etc....
How a pond freezes needs to be studied - but in short, I can tell you that it all surrounds two important ideas.
1) Water is densest at 4 C. It is less dense below 4 C and less dense above 4 C. Hence, really cold water at 4C is DENSER than 2 C water! Yep! Keep that in mind.
2) The entire pond of water will reach a temperature of 4C (layer by layer) as the air cools. Once a layer reaches 4 C it sinks and is replaced until the uppermost layer reaches 4 C. That layer can't sink (as all other layers beneath it are already at the densest ). This uppermost layer continues to cool to 0 C and below and freezing occurs on the surface. AND given our understanding that water expands as it freezes, the increase in volume allows ice to be LESS dense than water - hence ice floats on / in water!
Okay, write me with concerns/questions. Okay? Have a grand break. Stay healthy - I will see you on Monday 24 March. Read the polymer lab....
Monday 10 March:
Assignments:
1) For the Monday we return from break, have your saponification report (questions 3 and 6) completed.
2) DON'T FORGET: Shortly after we return, your TOPICS for your FINAL PAPER need to be emailed to me for review. There are topics on the first page of this website, as well as topics found on the link towards the middle of page 3 of the notes. I have also offered up at least three different ideas in lecture and lab. Get going! Having the topic in on time is graded!
3) Be sure you have handed in all work as I only grade the on-time hard copy of work. Midterm grades are due next week!!!!!!
Sorry that this blog update is a touch late - but I have your chromatography labs graded as well as the first exam (The results are pretty darn good). So those will be coming back to you on Thursday. I shall begin the Analysis of Water grading and maybe have that ready to go as well.
In lecture, we have been going at the dimensions of matter. The dimensions of matter tend to incorporate those measureable or mathematical concepts which discuss the behavior of matter, in terms of phase, density, pressure, mass, volume, weight (when appropriate).
Most of the dimensions of matter have an arithmetic procedure (or multiple equations) which can describe what happens to matter as tempaerature, pressure, volume or mass change.
We are on page 27 - but if we take into account the two demos I did up in the lab room, I could argue that we chipped away at specific heat (page 31). But, we will go over specific heat separately during lecture on Thursday - never fear!!!!!
Now, our course is not about the arithmetic. What we are developgin is an ability and a vocabulary to deal with these behaviors of matter as we continue to study chemical reactions.
These behviors may deal with the compression of a gas volume, or the expansion of a gas volume. They may cover the floating of ice in water, or the change in weight as the gravitational field changes, or why metals don't melt immediately upon heating etc...
This began with an attempt to mesh the influence of pressure on the density of a gas.
In order to get started we did a fast review of density. Class members reported that they felt strong regarding the topic - and that seemed to be so with the first TRY THIS problem we attacked.
Under Pressure (thanks to Bowie and Mercury for a great song)
We moved quickly onto a study of pressure!
Pressure has a similar ratio to that of the density equation. In the case of pressure we discuss not just mass in the numerator, but the product of mass and acceleration. The denominator is area.
Pressure is measured by measuring the impact of a particle with the wall(s) of a container or some other defined, confined boundary.
Assuming we alter only one variable at a time, for our work, pressure of a gas increases with an increase in mass (which can be seen as an increase in the number of molecules, as more molecules translates into more mass), or an increase in acceleration.
Acceleration is going to be very sensitive to changes in temperature. Hence we may infer that hot gases may exert a greater pressure than cooler gases assuming a constant mass and area.
This means - to our everyday world - that we might just need to add air to our tires as winter approaches.
The confined air in a car tire cools as the temperature drops. Hence, the cooler gas exerts a lesser pressure of the tire and the tire "deflates".
By adding more air, we can manipulate the relationship of Pressure = (mass)(acceleration)/Area
by compensating for a decreasing acceleration value by adding a greater mass !!!!
See? We can begin to explain and/or predict the behavior of matter in light of some of the dimensions we measure!
Gases under high pressure, tend to have greater densities than they do under room conditions. This led us to discuss how an aerosal spray can works and why we never throw one into a fire!
Once these concepts had been investigated and one false start (I got stuck in Charles's Law for moment with aerosal cans ... phew!) we introduced the means by which we breathe under normal circumstances.
Hence a quick look at the function of the brain's medulla oblongata with respect to smooth muscle, the diaphragm, rib cage and then the lungs, we could attack the chemistry of breathing as outlined by the work of Robert Boyle.
Boyle's Law tells us that the pressure and volume of a contained gas vary inversely with each other. That means that as the pressure goes UP the volume goes down. Conversely, as the exterted pressure on a gas goes down the volume INCREASES.
Boyle's Law (P1V1 = P2V2) expresses that inverse relationship at constant temperature. That is; assuming P1V1 represents a constant, as P2 drops, V2 must increase (and vice versa) in order to maintain the equality with the other side of the equation, P1V1.
Thus, as the medulla oblongata inervates the diaphragm to drop, the rib cage rises, V2 increases, P2 drops below the value of P1 and air is pushed from higher outside pressure to a lower internal pressure, of the the lungs.
The medulla oblongata reverses the mechanics, allowing the diaphragm to return to normal (rise), the rib cage lowers, P2 of the thoracic cavity increases to a value greater than external pressure, and air is pushed out.
Rinse and Repeat for 100 years or more :-)
We discussed how heavy masses on the chest can interfere with the mechanics and how moving to higher altitudes can lead to High Altitude Sickness (Edema)
Within the context of our work, 2 units for pressure were introduced (the atmosphere or atm & kilopascal or kPa). I tend to use atmospheres when discussing pressure in our course - just a heads up.
We discussed that the atmosphere is in layers and that we live at the bottom of this ocean of air!
This ocean of air exerts approximately 1 atmosphere of presser (14.7 lbs/in^2 or 101.3 kPa) of pressure on us.
The amazing piece is that we push out with an equalizing pressure! Hey! Writing this blog reminds me that I may have one more demo for us!
As we descend into the ocean about 1 atm more is applied per 10 meters of depth.
So naturally, we needed to look at the breaking of a ruler! (See the video link at the bottom of page 24 and show your friends/family and explain it to them!)
Then we took some time out to travel up to the lab where the nature of a liquid's volume was demonstrated to the tune of Twinkle Twinkle Little Star (thank you W A Mozart!).
We then took a minute out to heat/boil some water in a paper cup via a bunsen burner as a demonstration of the high (very high) specific heat of water!
Recall that the specific heat is a value expressing the amount of energy (joules) required to change 1.00 grams of a substance by 1.0 degree Celsisu (or more specifically, 1 Kelvin ... but let's not lose any sleep over this).
Okay! Write with questions and / or issues.
Thursday 6 March:
Class began with a review sheet (see the Everyday Notes tab ), Practice : Concept of Charge. Folks tell me that more of this type of activity is wanted. I will work on a vocabulary piece - and we shall see where that takes us.
Lecture focused upon the Dimensions of Matter. We reviewed the nature of the term, mass, by referring back to the quarter in the cup demonstration and the concept of inertia.
Allow me to state that I was quite impressed by how readily class members relearned / recognized this past work.
On Monday, I may try to get us up to lab early to try a demonstration - especially one regarding volume. Let's see how that can work.
We spent a fair amount of time with the dimension of weight. The definition of weight really surrounds the effect of gravity on a mass. We messed about with the link to the website exporitarium (link at the bottom of page 20) and tried to thread together that mass does not change but weight can as gravity changes.
We also chatted about the misunderstanding of gravity as "pulling us towards a center" as opposed to gravity as the result of the warping of the "fabric" of space-time. And that went pretty well! As one class member said - "It sort of makes sense" . So -okay!
We will pick up with density - just for a bit and then take a look at pressure. With that we shall learn how we breathe!
Okay! We are up to page 21 of the note packet.
LMK what you are thinking . Write me with questions / thoughts.
Monday 3 March:
Assignment:
1) Don't forget that your test is due on Thursday 6 March. If you are absent for any reason, email me a copy of your free responses using MS Word (not Google Docs) and send me a typed list of your multiple choice responses. That stops the clock and gives you some time to get a hard copy into me.
2) For your lab report on Acids/ Bases / Buffers you need to answer questions: 1, 2, 4, 5 and a reflection. Follow the template from the Introductory Packet (page 7). Be sure to cite your research sources by embedding those urls. As a bonus for the test, if you wish, you can answer question #3. There may be 1 or more correct answers. The lab report is due next Monday.
The first half of our lecture was dedicated to the Concept of Charge. The Concept of Charge explains the charge of an ion and teaches us how to interpret that charge. We are on page 19 of the notes.
Hey! Do you know why you can never trust an atom? Because they make everything up! (ba - dup- pum)
Okay, let's begin with a neutral (in charge) atom.
I tried to jumpstart your understanding of the structure of the atom to a metaphor of a castle on a hill, surrounded by a town.
The castle represents the nucleus. In reaction chemistry, the nucleus is stable and does not change in terms of the number of protons.
The surrounding town represents the electrons. In reaction chemistry, the electron number CAN change. That is -roughly speaking - we can add electrons or take them away.
In short, the protons (the atomic number) provides a positive charge, which must be equaled by the number of electrons, giving us a negative charge. The positive charge due to protons and the negative charge given by the electrons must add up to 0, for an atom.
Thus, a proton is assigned a positive charge of +1 and an electron is assigned a negative charge of -1.
Protons are found making up the nucleus while electrons are found in a volume of space beyond the nucleus.
Atoms must have an equal number of protons and electrons.
IONS (and these little devils are the real issue) have an UNEQUAL number of protons and electrons. Ions can be assigned a + charge or a - charge.
Lastly recall that a charge of an ion indicates what subatomic particle is in EXCESS.
Thus, a positive charge indicates that there are more protons than electrons, because electrons were lost by the original atom.
A negaive charge indicates that there are more electrons than protons, because electrons were GAINED by the original atom.
We did a fair amount of practice and we shall do some more on Thursday.
We then segued to our topic of mixture - using petroleum. We lightly discussed drilling vs refining and pretty much put a wrap on the idea of mixtures.
Okay, I think that's it.
Write me with your questions/ concerns / questions .... ! See you Thursday.
Thursday 27 February:
I have a few thoughts on this last lecture session.
1) There was a great deal of chemistry introduced into our conversation. Recall that the overarching idea here is the concept of MIXTURE. With that I have been trying to develop our understanding of just how common and ubiquitous mixtures are in our lives. Acid solutions (a form of homogeneous aqueous solutions) and Basic (alkaline) solutions are important examples.
With that conversation as to what an acidic solution is there came a number of new ideas.
a) The first new concept stated that pure water can break down into H3O^+1 and OH^-1. This occurs to a very small amount, measuring at about 1 x 10^-7 at room temperature. It is from this value that we get our value for the pH of pure water under normal conditions as 7.
This led us to a quick look at the pH scale as expressed by Soren Sorenson's work.
The scale runs from 0 to 14. 7 is neutral (as in pure water ... due to a balance between the H3O^+1 and OH^-1.
A value less than 7 means the solution is acidic.
A value greater than 7 implies the solution is basic (alkaline)
b) An acid is a compound which when added to water INCREASES the concentration of H3O^+1 .
Compounds considered to be acids do this by donating a H+ ion from their structure to water molecules. H2O becomes H3O+1
For the most part, many Arrhenius acids are easy to identify (on paper at least) as they have a formula written with H as the first element: HCl, HI, HF.
Arrhenius acids may be strong (they give up all their H+) or they may be weak (only a fraction of the acid molecules give up a H+
c) The second concept dealt with alkaline or base (basic) solutions. In terms of Arrhenius Theory, a base is any compound which can INCREASE the OH^-1 concentration when added to water.
Classically bases are compounds made from metal species bonded to OH, such as NaOH (Drano), KOH, Ca(OH)2 . Bases can be strong or weak as well.
We briefly discussed how Drano works - by converting fat (lipids, grease) into soap! Per a classmate's question, we found a video that gave a reasonable visual.
d) Organic compounds called alcohols, in which a carbon is bonded to OH (C - O-H ) are NOT alkaline. They ARE NOT considered to be bases.
The OH group does NOT come off when an alochol is mixed into water. The C - OH bond is relatively strong, when added to water. That OH can become reactive - but not by merely dissolving in water.
Conversely the C - H bond that we see in organic compounds does NOT imply the compound is an acid! That C - H bond is TOO STRONG to break when added to water.
So we begin to see differences in chemical activity when metals are bonded to O-H or when Hydrogen is bonded to nonmetal species other than carbon.
Our study of chemistry has begun to take on many layers.
2) My next thought is that I think I shall stop and try a little lesson regarding those positive and negative charges we needed to use while discussing acids and bases.
So our talk re: pretroleum products (especially oil) may need to come at the middle of our next lecture.
Okay - I think I shall end here. I suspect Monday's lecture will help to clear up any remaining confusion - but don't hesitate to write with your thoughts or questions.
See you soon!
Monday 24 February:
Assignment:
1) A take home quest was handed out. Be sure to read the directions. It is due at the start of class on Thursday 6 March.
2) Answer questions 3,4, and 5 for the lab report on the Water Analysis lab. For question 4, be sure to research both chlorine and fluoride. You should develop a rather complete answer which highlights the benefits and the concerns for both. You are then to take a stand as to what you would do should you have control of the situation with respect to their addition to a local water supply.
Well the lab went splendidly folks. I think you each saw a number of chemical reactions - as proven by a few bold color changes and the production of precipitates.
We had a chance to touch upon the colors of fireworks as the colors produced are linked directly to the metal ions we studied in lab. The one exception is the color white. That color tends to be produced by using the actual metallic state of the elements such as titanium, aluminum or magnesium. As these metals burn they tend to produce a bright white light.
As to class we are still puddling through the concept of mixtures.
Class focused briefly upon the breakthrough work of Dr. Kizzmekia Corbett. I was the work of Dr. Corbett and her team which pushed mRNA vaccines forward to the point of useful practicality. She conceived the idea to "wrap" the mRNA in lipids, allowing for the mRNA to survive long enough for our bodies to create and effective response to that mRNA.
We then focused on the vaccine itself. Here are a few points to remember:
1) The vaccine does NOT have virus in it.
2) You CANNOT develop COVID from the vaccine.
3) The vaccine is a mRNA vaccine. This means that the mixture contains the directions (mRNA) to build a single protein of the virus. In the case of the COVID vaccine, those directions were to build the spike protein of the virus (NOT the virus).
As our bodies read and begin to make the spike protein the immunity system comes to the recognition that this protein is foreign and we develop cells to destroy it.
After a week or two, all parts of the vaccine are flushed from our bodies. However, the immunity cells developed to recognize and destroy the spike protein remain in our body. Our bodies are now primed to call up and manufacture an immunity response very, very quickly - and thus, we can defeat an infection of COVID when needed.
As an side, we need boosters to deal with the changing nature of the virus. New (successful) strains of the virus have altered the spike protein (via evolutionary forces). The boosters are designed to account for these changes.
The vaccine is 9 to 11 different compounds mixed together. Hence, vaccines are mixtures of various compounds.
Once done we turned our attention to another application of mixtures - the work of Alice Ball.
Her groundbreaking work regarding an antimicrobial treatment for leprosy in the early decades of the 20th century, is a remarkable story of plant botanical chemistry. Her work impacts our topic in that chaulmoogra oil (a mixture) was successfully separated and manipulated to preserve effective antimicrobial activity via saponification and esterification. Both of these processes are covered in our lab work a bit later in the semester.
Okay! Write with your thoughts or questions. See you all Thursday.
Thursday 20 February:
Well, it certainly was an interesting evening's discussion. We did a great deal of rather sophisticated chemistry as I tried to answer a few questions.
But first - let's review the upcoming assingments.
1) Be sure to prep for Monday's lab re: Analysis of Water. We will test only two samples of water. I will make two samples of fairly awful aqueous solutions. You are welcome to test both of them. However, if you wish to bring in an interesting sample of your own (e.g. from your well), feel free to do so. You can test that and one of the samples I put together.
2) On Monday I will give out the first of your short take home quests. It will cover a fair amount of work and you are welcome to research, use your notes, work in a group. No short answers however, should be identical. You are to create/author your own answers - Yes, work with a friend, but create your own response. We will discuss its due date, when we see each other on Monday.
Okay, we are on page 15 of the notes. As I quipped - we are not getting through the packet quickly - but we are doing a ton of chemistry.
In terms of mixtures we emphasized :
1) Mixtures are physical combinations of substances (element /compounds)
2) Mixtures can be homogeneous or heterogeneous.
3) Mixtures do NOT have definite proportions of ingredients. Think of a toss salad. We can change the amounts of the ingredients at a whim.
4) The components of a mixture can be separated from each other MORE EASILY than the bonded atoms of a compound.
5) We can use chromatography to separate the components of a mixture. We can use filtration (as in making coffee) or boiling away water to separate the pure H2O (distilled water) from the materials dissolved in that water.
6) When materials are dissolved in water we call it an AQUEOUS SOLUTION. Water acts as a solvent.
7) ALLOYS are a mixture - they are NOT an aqueous solution. Rather they are really solutions of metals ... where one metal is merged (dissolved) into the spaces between a second metal.
Now, as an educator, I hate to have a client ask a question and in return find me asking them if I can put their question on hold until we get to that topic. I like to try to answer there and then - and yet I recognize clients may not have a full background . I try to take advantage of that desire to know...
Well last night was such a time. While taking questions about the homework, a classmate asked about molecules and covalent bonds.
Short answer: A covalent bond exists between two nonmetal atoms. A complex of two nonmetal atoms is called a molecule. Hence covalent bonding and molecules are closely associated.
A MUCH LONGER ANSWER:
A bond is considered to be a chemical union , made from electrons, in which a few things can happen. Bonds are often described as a form of potential energy (more on that later ... because there will be some sort of change or work involved)
I will mention two things that might result in terms of a chemical bond.
1) An atom can "take" an electron from a second atom. The loss of a NEGATIVE electron makes the loser into a POSITIVELY CHARGED ion and the atom that "takes" the electron becomes negative.
The opposite charges attract and we say an IONIC BOND has been made. Essentially an ionic bond is due to the attraction of oppositely charged species due to a COMPLETE TRANSFER (taking) of an electron.
We see this type of bond between metal species and nonmetal species.
2) Electrons can be shared. This type of bond is called a COVALENT bond.
Covalent bonds are made when atoms SHARE electrons. Neither atom has the ability to just "take" electrons from another atom. Rather, due to a weaker ability for either atom to "take" and hold onto an electron, many atoms share the electrons.
This sharing of electrons creates the covalent bond.
So assume two atoms A and B. In a covalent bond an electron from atom A is attracted to the nucleus of atom B. Meanwhile an electron from atom B is attracted to the nucleus of atom A.
The sharing may be equal or unequal. For instance, atom "A" may attract the electrons more strongly than atom "B" or they may attract the electrons equally....
This ability to take or share or just to attract electrons of a bond is well explained with the concept of
ELECTRONEGATIVITY.
The Pauling Scale of Electronegativity expresses the tendency to gain an electron of a bond using assigned values which run (roughly) from 0.7 to 4.0.
Fluorine is recognized as having an electronegativity value of (roughly) 4.0. This means that fluorine has an incredibly strong attraction for the electrons of a bond.
Cesium has an electronegtivity value of 0.7. Cesium is going to lose that electron. The low value indicates that cesium has virtually not abillity to snag an electron from some other atom.
When a metal of low electronegtivity reacts with a nonmetal of high electronegativity, the nonmetal tends to "take" the electron. The metal loses the electron, and the nonmetal gains it. This creates positive and negative charges and the two species attract each other, to create an ionic compound via an ionic bond.
When nonmetals react with other nonmetals, they end up sharing electrons as neither nonmetal has a dominating electronegativity value.
This ends up creating a covalent bond. (Hence, covalent bonds are tightly associated with molecules).
See? We are back at the SHORT ANSWER!!!!! But now, there is a "why" to go with it.
I figured I was done - but NOOOOOOOOOO.
Another student asked: Why does alcohol (like ethanol) evaporate so much faster than water?
I took the opportunity to explain this by citing INTERMOLECULAR FORCES OF ATTRACTION.
Short Answer: The molecules of water are strongly attracted to each other. This strong attraction between the molecules takes more energy to separate the molecules into the gaseous phase (to evaporate it).
Molecules of alcohol (ethanol) are NOT as strongly attracted to each other. Thus, it takes far less energy to separate the molecules into the gaseous phase.
A MUCH LONGER ANSWER:
BONDS are stong and exist between atoms or ions.
INTERMOLECULAR FORCES are weaker than bonds and exist between whole molecules, as a rule. (The strongest intermolecular force is about 5% of a certain covalent bond's strength.)
BONDS are like your shoulder joint ... strongly associated with your body.
INTERMOLECULAR FORCES are more like holding hands or walking shoulder to shoulder with someone.
(weaker than a body joint)
INTERMOLECULAR forces evolve AFTER bonds are made.
INTERMOLECULAR FORCES may also be explained using ELECTRONEGATIVITY (No wonder Linus Pauling won the 1954 Nobel Prize in Chemistry...)
Molecules MAY HAVE A PARTIAL DISTRIBUTION OF CHARGE. That means, that parts of a molecule may be PARITALLY possitive (a little positive) and PARTIALLY NEGATIVE (a little negative).
These areas of partial positive /negative attract the partial positive / negative areas of a SECOND or THIRD molecule.
This attraction creates the phases : strong intermolecular forces create a solid, moderately strong intermolecular forces create a liquid phase and weak intermolecular forces create a gaseous phase.
Water molecules (for reasons we did not discuss) have STRONG intermolecular forces between their molecules due to the partial charges on oxygen and hydrogen atoms. It takes a fair amount of energy to turn liquid to gas.
Ethanol however, has much weaker intermolecular forces, as we saw with its molecular structure. Hence, ethanol turns from liquid to gas much more easily as it requires less energy to do so.
See? We are back to the SHORT ANSWER ... but now, with a "why" !!!
Along the way we discussed issues of density.
Why does ice float on water? Why was it lucky for life on Earth for ponds freeze with ice at the top?
We discussed that items of lesser density tend to float in materials of greater density. Thus, icebergs with a density of (on average) 0.917 g/cm^3 will float in saltwater with a density of about
1.0 to 1.03 g/cm^3
Helium balloons float in air and oil floats on top of vinegar ... all due to density differences.
Materials of lesser density float in materials of greater density. Recall that golf ball floating in saltwater from a few weeks back. The golf ball's density is less than the density of the salt water mixture I created. Hence it floated.
Anything which sinks in water (like our aluminum rods from lab) must have a greater density than water.
Okay! Write with questions / issues! I enjoy hearing from you!
Thursday 13 February:
Assignment: Work through some of the problems on pages 13-14 of the notes. The answers are given. Do as many as you feel you need to do - check your answers. Bring in your questions or email me!
Lecture dealt (essentially) with a continued conversation regarding the identification of organic and inorganic compounds.
It included the general idea that organic compounds will have: C - H which means carbon atoms bonded to hydrogen atoms with a covalent bond.
I know we have yet to learn about covalency in bonds, but I am simply trying to get you used to the idea that the dash (as in C - H) represents a special type of bond called a covalent bond. We also touched upon the idea that electrons are shared in a colvaent bond. (Recall I spiral - so I toss out an idea and circle back to it in time at a different level).
We touched upon ionic bonds. An ionic bond is between charged (+ and -) species. The big take away is that we will find ionic bonds in compounds that have a metal bonded to a nonmetal.
This of course brough us back to the use of the Periodic Table of Elements.
We took notes on the term molecule. A molecule is a structure made of nonmetals made from more than one nonmetal bonded to another nonmetal via a covalent bond.
Not all molecule are compounds. CH4(g) is a compound, an organic compound, and a molecule, with/due to its nonmetal composition and covalent bonding.
O2(g) is an element, but has covalent bonding between the atoms of oxygen and is a molecule (because both of the the oxygen atoms are nonmetals).
NaCl(s) is a compound, and inorganic compound but has ionic bonding, due to a metal and a nonmetal.
SO2(g) would be best described as a compound, and inorganic compound, a molecule (due to shared electrons between nonmetal atoms).
It's a fair bit of information - and it sounds as though it overlaps - so let's try it this way:
Nonmetals bonded to each other create a molecule.
Sometimes the molecule is a compound AND sometimes we could end up with a molecule which is an element.
1) If the two nonmetals are DIFFERENT nonmetals then we have a molecule (they are nonmetals) AND a compound (they are different elements).
2) If the two nonmetals are from the SAME element (O2) then we have a molecule AND an element.
3) If there are at least two different nonmetals and some include C bonded to H, then we have a molecule (everything is a nonmetal), AND a compound (the atoms are from different elements) AND it's an organic compound (due to C - H).
4) If there are at least two different nonmetals but a LACK of C bonded to H (like SO2, PH3, CO, H2O ) then we have a molecule (all nonmetals), AND a compound (they are different elements), but probably and inorganic compound as there are no C -H covalent bonding.
5) When there is a metal in the compound, then it's an ionic compound with ionic bonding and an inorganic compound.
Yikes! Recall we can each be described by multiple adjectives - so too can we describe matter.
I think I will leave the recap there. Note the use of terms. Be familiar with the vocabulary:
Write with your questions. PHEW!
Monday 10 February:
Assignment: 1) For you Chromatography lab be sure to answer questions 1, 5, 6 a and b from the lab manual and the application question re: blood panels. The entire assignment is on your pre-lab. You have a hard-copy of that and it is on this website under the first tab, as well. Turn your report in next class (We have Monday off). Be sure that data table is made with MS Word, Excel or some other program. No hand-drawn tables!
Assignment: 2) For those offered a chance to re-write their Alchemy lab report, email me the completed report. I will scan it over for the necessary changes. I hope this will save you the cost/effort of reprinting the entire lab for just one question or so. Those changes should reach me by Thursday 13 February. This is a one-time deal ;-)
I think you can now see how I grade - via comments (!). This is one reason why I want hard copies of your work. I want to interact with your work - dialogue with you. If you can't read my ancient hieroglyphics - see me - ask a question. With the exception of emailing the Alchemy re-write, keep the hard copies coming in.
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Well another lab down and your work looked terrific. You were safety conscious (everyone had their goggles on). People worked well together. You took on the challenge of that data table beautifully! It was great!
Remember, the chemical dyes looked old - so in case of a poor correlation between your standard tests (the knowns), and your unknowns - don't worry.
Your job is to disscuss that disconnect - mention it - try to explain it or suggest an improvement. The learning is in the thinking - not just the "right answer".
The lecture did not see us move very far into the notes - but I felt that, class members believed the conversation which did evolve was worth having.
You need to let me know if I am wrong or right on that feeling. We sort of went down a number of rabbit hole as we worked through a bunch of complex (and strong) questions.
Has anyone else begun to see that we are spinning webs, interconnecting threads? We have, to my mind, begun to network information - resulting in knowledge.
Frankly folks - those questions were wonderful. It is great to have you stop me and ask to repeat something. It is wonderful for you to ask about a topic that is in your head. I have an idea of what I want to get through - but I am working to blend into that idea, the pieces you want/think about. Keep that kind of; respectful, positive, engaged behavior going! Bravo/Brava!
We are on page 10 to 11 of the notes.
Now, for those folks not in attendance, you may wish to ask a neighbor for their notes - as many things written down in class were not found directly in the notes. The applications of NaI, complete combustion, the purpose of a car's carburetor, the hormone thyroxine, goiter, iodized salt etc...may prove interesting.
We began with a review of subtances (elements / compounds) and mixtures.
There was a review of the metaphor of a mixture as a sentence, made of words and letters (compounds and elements) in a non-definite proportion.
We reviewed homogeneous and heterogeneous.
We then made our way into some awful definitions re: inorganic compounds and organic compounds.
Allow me to approach the topic a bit differently. I am going to simplify it a bit and I will begin with organic compounds this time.
An organic compound will have carbon bonded to hydrogen ( C - H ) via covalent bonds (electrons are shared) or be some sort of derivative of that. I will explain the idea of the derivative later on Thursday (should the snow allow!).
So, organic compounds are:
1) Compounds: There are two or more different elements in a definite proportion .
2) Two of the elements making up the compound will be (as a rule for our classwork) CARBON BONDED TO HYDROGEN.
C and H may be the ONLY elements: CH4(g) methane (a.k.a natural gas).
There may be atoms of OTHER elements as well (e.g. O, N, Cl, F, S, Br) BUT for our work there will be C - H somewhere in the structure.
The line ( - ) between the C - H represents a covalent bond (shared electrons). Know This!
For instance we can take a look at glucose (C6H12O6). Notice there are many C-H bonds as well as O-H bonds or C-O-H bonding. The presence of the C-H bonds are what make this an organic compound!
I think that is something you should memorize.
Organic compounds can undergo a number of chemical reactions.
Two important examples are Complete Combustion and Incomplete Combustion.
Complete combustion is pretty much what happens in terms of a fire or what goes on in your house furnace (assuming you don't have electric heat)
In a complete combustion reaction an organic compound is reacted with enough oxygen gas to produce carbon dioxide, water and lots of released energy.
For example: CH4(g) + 2 O2(g) --> CO2(g) + 2 H2O(g) + kilojoules of energy
Complete combustion produces carbon dioxide and water. Memorize this!
Incomplete combustion occurs in a smoldering pile of embers or the internal combustion engine of a car. In this reaction, oxygen is limited and carbon monoxide (not carbon dioxide) is produced along with water and a limited amount of energy.
We discussed types of furnaces in our homes, ranging from oil burning furnaces to natural gas forced air furnaces to electric heat, steam heat etc.
By the way - If I remember I am going to bring in my copy of McPhee's Encounters with the Archdruid and read you that first paragraph about the mountain cabin.
Inorganic compounds are compounds (2 or more different elements in a definite proportion) BUT they LACK C - H covalent bonds.
Many of these inorganic compounds may be further classified as salts (for example). A salt is produced when an acid reacts with a base (more later).
The most well known salt is TABLE SALT or sodium chloride NaCl(s).
There are no C - H bonds in NaCl . Hence, NaCl(s) is an INorganic compound.
CO2(g) is an inorganic compound (NO C-H bonds)
H2O2(l) is an inorganic compound (No C-H bonds)
So, for our class, Organic Compounds will have at least , C - H and Inorganic Compounds will NOT have
C - H covalent bonds.
You can tell what something is - by what it is NOT!
Yes, there are exceptions - but we are not going to need to worry about them. Learn the above recognition skills (as they are not so much definitions as recognition skills). Those skills will serve you pretty darn well.
We then discussed iodized salt working off of a question from a class member.
Iodized salt is a MIXTURE of NaCl and NaI.
The NaI is added to NaCl to supplement our intake of iodide (a negative or reduced form of iodine atom)
so that the hormone thyroxine is produced.
We discussed the position and purpose of the thyroid gland as well as the requirement for iodide to make thyroxine.
The absence of iodide can create a goiter, hypothyroidism and hyperthyroidism.
Iodized salt is quite common in the supermarkets of the East Coast of the USA as our soil is lacking iodide. Thus, the fruits and vegetables grown here have a lesser concentration of the necessary iodide nutrient/mineral. The US government first sanctioned the use of iodized salt (mixture) way back in the 1920s. (No, I do not recall them doing it.)
It was the Chinese who were first to note that goiters decreased in size with an increased intake in seaweed. Seaweed happens to be high in iodine! See the NIH at: https://pmc.ncbi.nlm.nih.gov/articles/PMC3509517/
Okay! That's the short version! Holy Heck - I thought lecture was quite far reaching. Let me know what you think.
Write with questions/concerns.
Monday: 3 February: You did so very well on that darn density lab! Let me tell you what I saw:
I saw you stay focused during the pre-lab and I think you really tried to master the vernier calipher. Your measurements prove it!
Did you pick up as to the consistency that existed between the volume calculated with measurements from the vernier caliper and the volume obtained from the graduated cylinder? Couple that to the fact that your values for density were really good. You were fire! Bravo and Brava!
Assignment: For your density lab report, be sure to follow the template I gave you, and be sure to complete questions 1, 3 and 4 in the green lab manual. Be sure to answer question 1 using your AVERAGE VALUES! Don't forget your reflection. I am going to really look at it for how you handled the challenge of the vernier caliper. (What made you so successful / gave you heart ache?) . Staple your data tables with your averages to your report.
If you gave me a "hard-copy" of your alchemy labs , I have graded them up. I shall give them back to you on Thursday.
Some of you were Mary Poppins ... Practically Perfect People (or at least your work was practically perfect). Many of you are invited to fix some of the pieces that are missing. Some forgot the reflection, others forgot the alloy question found on the pre-lab.
Virtually everyone cited their sources. Abso-freaking-lutely Fabulous! It is so good to see.
I offer a re-write for this first lab only, in simple recognition that it is your first attempt. So we shall discuss this in class on Thursday.
As to class, we put a wrap (for now) on Big Idea #1 LCME (Law of the Conservation of Matter and Energy).
We then attacked the classifications chemists use for matter.
We are up to page 9 of the notes.
There are SUBSTANCES & MIXTURES. Matter is generally going to be one or the other.
Substances are either elements or compounds . I spent a fair amount of time trying to get you to recognize when you are looking at an element or compound, when reading/researching articles.
A symbol made with only one type of capital letter is going to be read as being an elemental substance.
O2(gas), Na(solid), etc.
The atoms of an element all share a common atomic number (or, they all have the same number of protons in their nucleus).
I divide the elements into 4 categories, loosely based upon what they do with their electrons.
Metals or Metallic elements tend to lose electrons to other non-metal atoms.
Nonmetals tend to gain electrons from atoms which hold onto their electrons more weakly (very often metals).
Metalloids can do a little bit of everything. We don't work very often with metalloids as they are a funky collection that even have chemists arguing.
Noble Gases don't really lose or gain their electrons. There a a few minor exceptions - but the big picture is that they have all the electrons needed and these elements tend NOT to make compounds.
A symbol made with two or more DIFFERENT capital letters in a strict ratio will be read as being a compound substance. Examples are compounds like H2O(liquid), or C6H12O6 (solid)
Recall that comound substances (or just compounds) can be decomposed into simpler substances and have chemical bonds (a form of potential energy) between the species that comprise the compound.
The elements that make up a compound tend to lose their individual properties/identities.
To use the metaphor I was developing in class:
An element is like a LETTER of the alphabet: whole and unique
A compound is like a WORD. There is a fixed ratio between the letters (elements) . Change a letter (element) and you change the compound.
Mixtures are the most common experience for us. They are physical combinations of substances.
A mixture are like a sentence - any number of letters and/or words strung together physically. The number of words can be changed.
Today I have been thinking that to better grasp what I mean by a physical combination - we should touch on what we mean by a chemical reaction. You can know what something is, by what it isn't.
So I may just attack that issue on Thursday.
Okay, I feel that's it. Write with questions. I will see you Thursday. It was a very good Monday. Stay safe out on the roads come Thursday - there will be some snow.
Thursday, 30 January: Well we are well into the first note packet. I needed to jump around a touch only to help prep us for Monday's lab on measurement and density.
First, a little housekeeping:
1) Two assignments are due on Monday:
a) Your lab report for your Alchemy Lab is due. The template for writing a report is in the introductory packet. There are three questions to answer: Questions 1 and 2 from the green lab manual and the third question regarding alloys in history (found in the prelab I handed out ,and you can find it here on this site if you need to do so). You need to cite your sources for question 2 - so don't forget. There is also a reflection to write. Recall that the reflection is about the interior dialogue you had during the lab and/or the conversations you had with a partner. What made you successful? What don't you understand? What allowed you to get through the experience successfully, or what held you back?
b) Your 5 questions piece. This does not need to be grand. I would like to know some questions you might have so I can build pieces into the course.
Okay, on to the lecture.
We focused upon two concepts
1) Big Idea #1: The Law of the Conservation of Matter (Energy and Charge)
2) Matter has dimensions - measurable qualitites such as; Mass vs. Volume and Density
The Law of the Conservation fo Matter, Energy and Charge surrounds a basic idea in chemistry.
You cannot get out what you did not put in.
You cannot get out MORE than you put in.
You cannot get out LESS than you put in.
Matter (energy and charge) cannot simply disappear via reaction chemistry activities. Each is conserved.
Matter may change phase (turn from a solid to a gas, or new bonds may be made between atoms givng us new compounds). But the total amount of matter does not change.
Energy may convert from mechanical to infrared and be transferred (Recall rubbing our hands together and then putting them to our faces.).
We are going to see this Big Idea over and over again throughout the course.
That conversation brought us to page 6 of the notes.
We then hopped over to page 22 of the notes to discuss mass, volume and especially density.
Density is the compactedness of matter. Density is a ratio (a direct proportion) between mass and volume.
Under constant tempereature and pressure, as mass increases, so too must the volume of the sample increase.
They scale with each other - hence density becomes a constant. As we (hopefully) will see in lab, the density of a long rod of aluminum metal will have the same density as a small rod of aluminum metal.
Sure the longer rod is more massive - but it also has more volume when compared to the smaller rod.
Hence the density should be the same.
Now mass is a tough idea to define. I attacked the definition with a demonstration of what might be termed inertial mass. (That was the coin in the cup demo.) I compared the quarter to the jar of pennies.
It was much too difficult to sweep the cardboard out from under the jar of pennies - hence the jar of pennise was more massive relative to the quarter.
With this work regarding the concept of MASS, I took a fair amount of time to differentiate between mass and WEIGHT.
WEIGHT is concerened with mass in a gravitational field. The word weight and mass seem to be interchangeable but that is only because the gravitational field on Earth is relatively similar wherever you are. There are some hiccups as at the equator, the poles , in Death Valley or atop the Himalaya Mountain range. But for most of us, the gravitational field pushing us down (hmmmmm) is not terribly different from place to place.
However, weight and mass are not really the same thing. When we go to the Moon, our mass is constant but our weight is less because the gravitational field of the Moon is 1/6 that of the Earth's. Hence, the muscles built here on Earth can do amazing things on the Moon - for a while, at least. (Things change ... "da-da-da-ta" ... more to come later!!!!!!
We then did a little density demonstration. (The golf ball in the graduated cylinder). The gold ball only sank so far - because a mixture of GREATER density (saltwater) was at the bottom of the cylinder.
Okay - Monday gets us a little story about a famous power couple of the 1700s and moves us into an introduction regarding the types or categories of matter.
Write with any questions! You did really, really well in class - you were engaged and focused. Bravo and Brava!!!!
Monday, 27 January :
We began lecture and made it up to page 5 of the notes.
The main theme of the evening was on differentiating between matter and energy.
We began however, with a look at the definitions of science and then of chemistry.
Science is a process - not just information. Science is the process of constructing understanding of the the universe. We need data, facts, the information - but science weaves information into knowledge - something used to make predictions or to further explanations.
I grant you that focusing on such a definition may seen a bit different - but it may help you to grasp what I want to do with our time in class. I want to move you away from simply memorizing facts (don't become a telephone book) to using information to build ideas/understanding of the universe.
As an aside - don't get upset when "science" tells you something has changed. Science hasn't lied to you - it has simply refined its process and learned something new. Science is dynamic - it's all about life long learning.
I want you to be part of that dynamism! I am expecting you to think! To construct understanding. That's a pretty big goal.
If you recall the notes - You and I ARE the universe, expressing itself as human for a time. We are the stuff of stars, the stuff of ancient, ancient matter and energy.
With that, we took a minute to see that chemistry deals with matter in terms of its properties & composition. The reactions (changes) matter undergoes , and the energy associated with those changes.
We spoke a bit about reaction chemistry (all about those electrons) and nuclear chemistry (surrounding the protons and neutrons).
This led us to taking a long look at matter - anything with a mass and volume. (A fascinating - but more advanced question - is asking why matter has volume ... why do we or any type of matter take up space? That answer is found in the Pauli Exclusion Principle!!! More later)
However, when I was a student I found that idea of mass and volume a touch "out there". I couldn't wrap my mind around it's true implication - so I offered everyone a metaphor.
Matter is anything we can put into and keep (for a reasonable time period) in a balloon. As I said, all metaphors fail at some point - but I like that idea of matter and balloon. It's a good initial metaphor of what we mean by mass and volume.
Using a balloon I can imagine more matter means a greater volume (the balloon stretching into space) and a greater mass. I stopped for a second to just to mention that mass and weight are not really identical - more on that later.
Anything which is not matter, is probably energy - as we can know what something is, by what it is not!
Energy is the ability to create a change or to do work.
Work is that whole thing about force and distance (W = F x d). I threw a pen ... or even better, for our HPX majors ... how muscle contraction can be used as an example of work (energy), by allowing actin and myosin fibers to slide or move over each other. Energy was used to manage that change in position.
Excercising uses energy!
I like the bit about creating a change. I can understand that much better with ideas like photosynthesis, where sunlight (the energy) creates a change in the structure of carbon dioxide and water to produce glucose.
Now, while working to develop a grasp of matter as having mass and volume we took a side road into the work of Einstein.
And I sort of feel that side road can be valuable. As I said in class - we could look at matter as highly, insanely, organized energy. It's a neat idea - but not very practicle for first year students. So we worked away at trying to understand that, in chemistry, we sort of divide up matter and energy.
Another side road took us into the composition of the atmosphere.
We live at the bottom of an ocean of air! (Hmmmm)
That ocean of air is approximately 78% nitrogen gas, 21% oxygen gas with the remaining 1% made up of gases like carbon dioixde, carbon monoxide, helium, sulfer dioxide etc...
We inhale this ocean and we exhale some slightly different version of it. We use some of the oxygen we breathe in but our exhaled breath is still running at approximately 18%!!!!! (Remember .... mouth to mouth resuscitation!)
We wrapped up class with a little closure and we developed a list of some of the more salient pieces from the class . Ihope this blog reinforces some of that learning.
Remember ... Tell them what you're going to say. Say it. Tell them what you said. This works for class presentations, teaching, speeches - all sorts of things.
Lab went really well. Each of you were marvellous!!!!!!
It was a long night - full of safety rules, pre-lab, maybe some anxiety - and everyone handled it with grace and aplomb! (That's really old man-speak for - "You folks were jake" ... which is just old man speak for "You folks were cool" ....which really means "You did really well - be proud of yourselves")
Okay, write with questions and/or concerns. I will check my email periodically.
I look forward to seeing each of you on Thursday!
23 January: First Evening of Class!
Assignments:
1) Our first laboratory is next Monday evening (27 Jan). Read the introduction in your lab manual . In the introduction you will find the objective of the lab. You need this for your lab report.
However, the pre-lab lecture notes, the actual procedure we will use and the lab write up requirements are found in this document: Alchemy Lab (click here to open). You have a hard copy in your possession already. I am providing the link for your convenience if you need to get another copy.
BTW: I will have pennies for you. There is no need to bring in your own pennies. During lab I will get you goggles and we will also go over the safety rules for lab and sign off on the introductory packet.
2) Complete the assignment Five Questions (click here). This is due on Monday 3 February 2025 at the start of lecture. You have a hard copy in your possession - but I am providing a link nonetheless.
Now, onto class.
You were asked to pick up a copy of everything from the front desk. You have a copy of;
1) the Unit 1 Part 1 Note Packet
2) a periodic table of the elements
3) the Introductory Packet with the dates / procedures and expectations of the course
4) your lab manual
5) a copy of the alchemy lab (We do a slightly different prodcedure)
6) an assignment called the Five Questions
If you failed to get these artifacts or were you to lose something, you can find digital copies of 5 of the 6 on this website (either under the first tab, or under this blog tab). See me regarding a missing lab manual.
In class we went through the introductory packet. A number of points were highlighted. This number indludes, but is not limited to:
1) this website and its use/organization
2) this course being a writing intensive course
3) the importance to be in attendance
4) the importance of the laboratory program
5) how to remediate missed classes when the day goes wrong
6) the importance of citation of source materials
7) grading
8) important dates
Okay - not much more to add. Timliness to class matters - so get in as soon as you can. My thoughts on this is that you would not be late for a lawyer or doctor's appointment if at all possible - so don't be late for your own education - treat yourself that well.
You can find me in our classroom most evenings before class - take the opportunity to drop in. Treat this like unofficial office hours. Come in, chat about class or tennis or art or cars or whatever might be on your mind.
Drop me an email with any questions. I look forward to seeing you Monday evening.
1) Don't forget the hardcopy of your test answers is due on Monday 5 May. I will grade it up and get back to each of you re: grades and such.
2) Our last 5 presentations occur on Monday - and then ...freedom, from me!
During lecture we focused upon ethanol and issues surrounding the production of and possible aid for a hangover.
We began by differentiating between ethanol (ethyl alcohol, grain alcohol) and methanol (methyl alcohol, wood alcohol).
Ethanol is the active ingredient, the drug if you will, found in liquor, beer and wine - essentially any alcoholic potent potable .
Methanol is wood alcohol and its consumption can lead to the destruction of the myelin sheathing of the optic nerve, and thus, blindness.
This led to a quick discussion of terms which seem to be unfamiliar to the class - but ones I think you may still hear from time to time ... such as; blind drunk, bathtub gin, moonshiner etc. Then again, perhaps you will never hear these terms - I am of a certain age ....
After a quick review of the organic, molecular and covalent bonding of ethanol we looked at the 4 Horsemen of the oncoming hangover:
1) The prevention of vasopressin (anti-diuretic hormone ADH) to release water back into the body. Hence, dehydration occurs.
2) The conversion to and subsequent buildup of a toxin called acetylaldehyde.
3) The glutamin rebound
4) Congeners
In short, drinking shuts off our supply of vasopressin (ADH) and we dehydrate. Body organs pull water from our spongy brain, and our brain shrinks in volume, pulling on membranes holding it in our skull. This causes pain and a great deal of the morning - after headache.
Ethanol is oxidized to acetylaldehyde - a nasty toxin with the seeming ability to interfer with everything from mitochondrial function to enzyme activity.
Now, our live contains a small supply of glutathione - the KING OF ANTIOXIDANTS ... a magical compound, with the ability to turn the toxic acetylaldehyde to acetic (ethanoic) acid and shunt it out of the body.
However, the supply of glutathione is very small - and it takes time to reconstitute our reserves. Hence, anything we can do to help resupply it - is a good thing. Glutathione is a pretty standard organic molecule, with C, H, O, a little N and oddly, Sulfur (S). Hence, the key is to get sufficient sulfur to help rebuild our depleted supply of glutathione. Hard boiled eggs with their rich supply of a sulfur-containing amino acid called cystiene can do the trick - per the rumors. The best case is to avoid excessive drinking all around!
While ethanol affects an inhibitory neurotransmitter, referred to as GABA, and thus weakens our muscular control, speech etc, we also fail to supply sufficient glutamine (an excitatory neurotranmitter).
Sometime during sleep - as the alcohol is oxidized away, the glutamine rebound occurs - causing anxiety, stimulation, lack of sleep etc - adding to the woes.
The confusing critters, congeners are the last aspect. Congeners are "born with" (as in the medical term, congenital) the fermentation of alcohol - especially the dark liquors.
Some congeners help ease the natural bleeding of the stomach with the consumption of alcohol - while others may be mild toxins. They are a mixed bag.
Don't over imbibe . Always have a ride - or better yet, keep to soda and be someone else's ride.
Okay - write with questions ... See you Monday for a little nutrition and the evals.
Monday 28 April
Assignment:
1) Your last test (there is no Final exam during exam week), was given out . A hard copy of your responses is due on Monday 5 May. If you didn't get a copy - please email me. I will email everyone with results and grades. Be sure to word-process (type) out your responses. And, yes, it is missed numbered. There are only 11 questions - but because I tossed question 10 and never renumbered, the numbering is off. Don't sweat it ... just be sure I know what you're answering.
We began where we left off with vaping. And I think I have abandoned all pretense of neutrality on the issue. This stuff is simply a trifecta of bad.
The three issues surround that :
1) the nicotine content. Nicotine is an alkaloid and natural pesticide (for the tobacco plant) and variations (derivatives) are used heavily in agriculture.
While the use of nicotine itself as a pesticide has decreased derivatives made from nicotine, called neonicotinoids are used instead.
I re-emphasized the interpretation of a skeletal formula, using diagrams of nicotine as an example. Don't let those diagrams freak you out. Every carbon requires 4 covalent bonds and at every vertex of a diagram (like nicotine or benzene) there is a carbon and possibly up to two hydrogen, unless otherwise indicated.
2) The nicotine is soluized (dissolved) in a an oil carrier. This fairly homogeneous mixture is heated, vaporized and carried into the lungs via inhalation. Oil in our moist, thin respiratory system, does not belong. Oil and water do not dissovle into each other. This build up of oil is believed to compromise efficient gas exchange between the blood and gases of the lung.
3) The metal coild is heated ( by a battery) and over time the metal can corrode (or become oxidized). This means that the nickel or chromium in the coil can lose electrons to oxygen. These ions can be swept up into the inhaled stream of the vape. These ions can be carried into the lungs - and the various ions have carcinogenic potentiality.
With that done we moved onto a look at a number of compounds which use petroleum - derived benzene as a building block. This led us to a few poor jokes and ultimately a look at the function of analgesics (pain reducers) such as the NSAIDs and Tylenol (which is not an NSAID as it lacks the ability to deal with inflammation.)
We also took a look at folate and folic acid . Folate is the naturally occurring form of Vitamin B9 while folic acid is the synthetic form. The CDC has a very interesting video regarding the fortification of fooeds with folate.
It's really pretty good - and worth the 6 minutes or so - just to educate yourself.
Check out: www.cdc.gov/folic-acid/about/index.html
Scroll down about 2/3 of the page and you will see the video. I can't seem to find this exact video on YouTube, so I am providing it here in a slightly clunkier manner.
Okay, that's about it. Write with questions - I will see you Thursday and we will attack alcohol and hangover.
Thursday 24 April
We wrapped up Unit 2 as we finished a look at Climate Change. I chose not to push us into the more complex rationale for climate change (e.g. I chose not to go into stratospheric cooling) - as I felt time was getting short.
On the board I developed a few statements that should have encapsulated prior work:
1) Visible light (ROYGBV) from sunlight passes through the atmosphere.
Yes, per our video on radiative balance, some sunlight is reflected back to space & per our conversation re: ozone, UV rays are stopped to some extent & blue wavelengths tend to undergo Raliegh scattering ... giving us a blue sky.
The takehome message is that our atmosphere is like glass when it comes to visible light. Much of the visible light from the Sun passes right through our atmosphere.
2) Sunlight (ROYGBV) strikes Earth's surface and it is converted to infrared energy ("heat").
So this point is important as it demonstrates, again, that energy can be converted from one form to another and/or transferred.
In this case, a form of kinetic energy (eg electromagnetic spectrum) is converted to infrared energy (another but different form of electromagnetic energy [eg kinetic energy].)
You know the term, heat, is misused here as the term is not identical in meaning to infrared energy. Rather the term, heat, refers to the process of transferring energy - but I am not going to win the battle of parsing the difference between the terms. Hence, infrared energy can be interpreted as "heat energy" for our purposes.
3) The surface of the Earth radiates (releases) "heat energy" into the atmosphere.
So to recap: Visible light strikes, is converted to heat and in turn that heat is released back into the atmosphere.
4) Infrared Active (IA) molecules are in the atmosphere (CO2, H2O, CH4). These IA molecules absorb the radiating "heat energy" (infrared energy) .
The kinetic infrared energy is converted to POTENTIAL ENERGY as the electrons of the bonds making up the IA molecules stretch, wiggle, bend. BUT THE BONDS DO NOT BREAK!
The bonds return to a more natural length, reducing their POTENTIAL ENERGY and having it CONVERTED BACK to kinetic energy (which really is just infrared energy.)
The bonds do not break hence, a cycle of absorption of heat energy and the subsequent release of heat energy back into the atmosphere , is established.
In short, this is the (misnamed) Greenhouse Effect. ( This is isn't how a greenhouse works - but I need to use the terms I am given.)
The Greenhouse Effect is a good thing - in that it warms the Earth and helps to allow life to flourish.
However, too much of a good thing is the problem.
The burning of fossil fuels deposits more and more IA molecules of carbon dioxide into the atmosphere. The presence of these molecules "trap and release" more and more heat energy in /into the atmosphere.
In turn, this increase in atmospheric temperature warms the waters of the Earth, increasing the rate of evaporation, depositing even more humidity made of IA molecules of water vapor!
As the atmosphere warms wind speeds can increase. Water temperatures can increase. Storms such as hurricanes form over water. The warm water heats these storms, increasing wind speeds even more, creating this monster storms.
The warming of the Arctic has destabilized / weakened the form of the Jet Stream. As the Jet Stream weakens colder Arctic air descends southwardly towards areas, like CT. This affects our winter months.
As the Earth warms, glaciers on Antarctica and Greenland melt, sending huge amounts of water into the oceans. Ocean levels may rise, in time, by 20 to 30 feet. The obvious impact on low lying coastal areas is obvious.
As the Earth heats, new deserts may form, impacting farmland/grazing land and thus disrupt food production. The wheat belt and corn belt of the USA may move northwardly towards Canada.
The increase in ocean temperatures has begun to affect the reproductive patterns of fishes and other marine life. This too will create disruption to food production / acquisition.
In all probability, it is projected that the Earth shall not heat uniformily as our climate changes over the next number of generations. New patterns will emerge. What remains / changes is not clear in my crystal ball.
Governments have considered using satellite - based mirrors to reflect sunlight away from the Earth, so as to help cool it. Scientists have considered the effects of seeding the sky to increase cloud cover so as to increase the albedo (the ability to reflect light) of the Earth.
We then began the new set of notes with a look at nicotine.
I introduced the terms, ALKALOID. An alkaloid is a plant-derived nitrogen containing organic molecular compound (ooh the terms!!!!) that can have a physiological effect on our biochemistry (good and bad
Nicotine (tobacco), caffiene (cocoa, tea plant, coffee), morphine (poppy), strychnine (seeds of the nux vomica tree), atropine (deadly nightshade) are examples of alkaloids.
We pick it up on Monday! Okay, write with questions!
Monday 21 April
Okay! We are just about done with this unit. On Thursday we shall wrap up climate change and move onto some mini-topics.
In this latter section on energy I have been trying to provide you with a number of applications as to how energy is transferred from source to sink/chemcial and/or converted into other forms.
For instance we now know that the Sun's visible light energy is the energy which penetrates our atmosphere and is converted into infrared energy.
The energies upon which I have been most focused are the various forms of the electromagnetic spectrum.
It is in this topic that I have been trying to marry ideas of electron activity, to bonding to infrared reactivity, to potential and kinetic energy.
What follows are a number of the take aways from this section.
1) Electromagnetic spectrum energy is due to the changes in energy of electrons as they move from higher levels of energy to lower (or more natural) levels of energy.
2) The form of energy released by chemical species due to these electron transitions depends upon the extent of that transition. The type of energy that is released is dependent upon the electron transition. Not all transitions are equal.
3) We can identify the energy released by the wavelength and frequency. Recall that the wavelength and frequency are inverses of each other - in that the greater the wavelength, the smaller the frequency.
4) While all electromagnetic energy travels at the speed of light (in a vacuum) , they may deliver differing amounts of energy due to differences in their frequencies.
5) Visible light can be divided into multiple wavelengths known as ROYGBV. Per our discussion of visible light, red wavelengths tend to have the longest wavelengths, thus the smallest frequencies. Violet wavelengths tend to be the smallest wavelengths and thus the greatest frequencies.
We also know from the SciShow video that sunlight is not uniform. It leans heavily towards the green frequencies. This fact may have influenced the evolution of green plants - in that green plants do not absorb much green light at all. Rather, the color we see is due to the rejection or failure to be absorbed by the electrons of the molecular compounds of the plant.
6) Our demonstration of the effects of visible light upon the precipitate AgCl demonstrated that visible light may indeed affect bonds, do work/create a change upon chemical substances. As we proved, the blue wavelengths had the ability to break the ionic bond of solid AgCl, decomposing the compound into solid silver (the black/gray specks) and chlorine gas.
7) Silver chloride hence is sensitive to various wavelengths of light. Silver chloride was/is used in old timey black and white photography. Due to its low frequency, and inability to affect photographic chemicals, red light is used in photographic dark rooms.
8) This sensitivity of bonds to various forms of electromagnetic spectrum energyies was seen again, as we learned about UVA and UVB light having sufficient energy to disrupt the bonds found in molecules of our skin.
9) This sensitivity was seen again, as we looked as x-ray energy being able to disrupt the bonds in DNA.
10) This ability to be absorbed/released or to disrupt bonds was seen in our study as to why the sky is blue. Atmospheric chemicals can absorb and release (without bond disruption), blue light. This is due primarily to the nitrogen in our atmosphere.
11) Lastly this theme of electromagnetic energy was seen again as we began our work on climate change. Certain molecular chemicals in our atmosphere have the ability to absorb infrared energy coming off of the Earth's surface.
These infrared active molecules include carbon dioxide, methane and water vapor. Gas molecules such as oxygen and nitrogen are far more sensitive to ultraviolet light and do NOT have a significant impact on what we term, the Greenhouse Effect.
In short, the electrons of the bonds found in infrared active molecules can absorb infrared energy coming from the surface of the Earth WITHOUT breakage to the bonds. These bonds undergo an increase in potential energy, and a resulting decrease in potential energy, by converting the absorbed electromagnetic energy back into infrared (electromagenetic or kinetic) energy frequencies.
This capture and release of infrared energy is the founfsdation of the process of the Greenhouse Effect, the process by which the young Earth began to warm .
Okay! We finish on Thursday .... Write with anything you wish!
Monday 14 April
(My apologies folks - this blog was not published (by me) when I wrote it. I must have closed down after writing it and never hit publish.
We are up to page 60 of the note packet.
Tonight was all about the electromagnetic spectrum - those energies released and associated with the movement of electrons as they move from a higher (excited) energy to a lower (natural) position outside and relative to the nucleus.
We spent a fair amount of time discussing the inverse releationship between wavelength and frequency.
The larger the wavelength - the smaller the frequency.
The smaller the wavelength - the greater the frequency.
The above relationship can be applied to explaining the high energy delivery of EMS energy in the form of ultraviolet rays, x-rays and gamma rays.
We watched the steel ball hit an anvil video (the link is in your notes) to try to drive home the relationship between wavelength and frequency.
We then moved back to the to look at the various forms of "light". I got off on a rant regarding bees and birds and polarized light.
ROYGBV helps to recall the wavelengths of visible light, with violet being associated with the smallest wavelength and greatest frequency of visible light.
Beyond violet is ULTRAviolet. The prefix ultra means , beyond to to the extreme of....
Ultraviolet rays (those absorbed during sun-tanning) have the energy (the ability to do work/create change) beneath the outer layer of skin.
UV B rays tend to penetrate to the lowest layer of the epidermis. Now, the epidermis is the outer layer of skin - but it is further divided up into "sub layers". UV B rays can penetrate down to the basal layer and create what you and I call sunburn, via the endothermic destruction of bonds.
UV A can penetrate deeper - beneath the epidermis and disrupt the cells of the dermis. UV A contributes to the destabalization of collagen and elastin. Translation .... UV A contributes to wrinkles and an aged look to the skin.
Recall collagen is the protein with a dependence upon Vitamin C, as the vitamin helps to deposit and convert hydroxyproline in the production of collagen.
UV A is also the culprit regarding skin cancer.
Now, I am not a dermatologist - but this is your professor's suggestion that you to speak to a professional (your GP or a dermatologist ) and get their opinions regarding the use of a good suncreen . Many suncreens are incorporated right into moisturizers and you know I have pitched the idea of moisturizers in the past ... But you speak to your doctor.
We then moved onto the idea of color and from whence color comes. We will also see on Thursday why plants tend to be green.
Okay - write with questions. Papers are due. See you soon.
Thursday 10 April
Assignments:
1) Thursday, April 17th your final papers are due!!!
This is a quick blog to write ... as we wrapped and reviewed a couple of concepts - and then began our work on the electromagnetic spectrum.
We are on page 58 of the notes.
We wrapped up work on exothermic/endothemic energy exchanges. I also worked to put in context a review on ground state electron configuration and excited state configuration.
Excited state configuration is important in that it ties together ideas such as:
1) potential energy can increase and decrease (via a conversion to some form of kinetic energy)
This idea involves:
2) as electrons move further from the nucleus, due to an absorption of energy, they occuy a higher level of energy.
3) the attraction of the nucleus for that electron still exists and that electron will return to its original position by losing potential energy. However, (and this is the learning), that lost potential energy is converted into kinetic energy, such as light or radio waves, or microwaves. This obeys Big Idea #1 The Law of the Conservation of Matter, Energy and Charge . Energy cannot be created or destroyed by ordinary chemical means - but that energy can be converted into other forms and/or transferred.
4) Hence, as an excieted electron moves from a higher energy level to a lower energy level, it releases energy along the lines of electromagnetic spectral energy... visible light, infrared, radio wave, x-rays, microwaves, ultraviolet waves
5) The forms of electromagnetic spectral energy are related to each other because they are each due to the motion of excited electrons dropping from higher to lower energy levels.
6) The range or extent of positional change dictates the type of electromagnetic spectal energy released.
The YouTube video I used to describe the above phenomena is not in your notes. However, I am linking the video (click here). We began around 10 minutes 30 seconds in the video and ended around 20 minutes into the video.
Armed with the visuals from this video we could link electron configuration, valence electrons, excited electrons, and the electromagnetic spectrum.
The discussion then shifted to the wavelength and frequency of electromagnetic energy.
All electromagnetic energy travels at the speed of light, (around 3 x 10^8 meters/second) in a vacuum.
So radio waves travel as fast as visible light waves in a vacuum.
The difference between the various forms of electromagnetic energy are those wavelengths, and frequencies.
And, as demonstrated in class - they are inversely related. This means that the smaller the wavelength, the greater the frequency. (More on this on Monday).
Radio waves have a large wavelength (like the size of a football field), whereas visible light waves have a wavelength around the size of a bacterium.
We can deduce then that radio waves have low frequencies and visible light has much higher frequencies.
These ideas were applied to why we needed to be careful as to how many x-rays we get taken per year.
X-rays have very small wavelengths thus they have an incredibly high frequency and can deliver a great deal more energy to a system in the same period of time as a radio wave.
Okay - that's it! Everyone should be working on their final papers. Those are due Thursday - 17 April!!
Write with questions.
Monday 7 April:
I
Assignment:
1) Your take home test is due on Thursday. If you are absent on Thursday, you need to scan or photograph you answer sheet and send it to me via email that night. That stops the clock and you can turn in your test the next time we meet. Be sure to "X" your answers. Read the directions!!!!!
I reinforced that you will see issues, surrounding exothermic and endothermic energy exchanges on your next test. I think it is fair to say, perspiration and climate change and reactions in beakers (like our practice problems) would be on that exam.
I felt last night was a big night for us - what with the problem set and the lab. I am linking a copy of the lab worksheet (click here). It has the orignial 4 reactions - BUT!!! I am including an answer sheet which also has that first demonstration of rusting iron I worked through with you on the board AND I have provided a "key" to the identification factors for the terms at the bottom of the answer page.
That worksheet is your lab write-up. So if you were there you earned 25 points.
Focus on your take home (one more to go) & writing your paper. Check those due dates in the Introductory Packet. Okay?
We are up to page 51 of the note packet.
We worked through the benefits of a Frayer Diagram. I urge you to consider creating some of your own.
We then went into the problem set. This stuff is not so obvious - however, I think through your continued questioning, I think we summed things up nicely.
Consider using this:
When the energy exchange is:
exothermic: as products are made, chemicals lose energy and the environment heats up.
endothermic: as products are made, chemicals gain energy and the environment cools down.
This works for chemical reactions and/or physical changes! Go back and look at the problem set ... try the questions without looking at your answers and see it the above helps. If not, drop me a line.
We then drew the link between the average kinetic energy and temperature. THEY MEAN THE SAME THING.
I explained why temperature is the measure of the average kinetic and not the system's entire kinetic energy - with my magnificient drawing of a thermometer in my giant beaker of science (say that with an echo)!
Recall that only an average number of molecules in the systemt interact with the temperature bulb .
We emphasized that energy moves from high to low (an that transfer is referred to as "heat")
We also reemphasized that there is no such thing as cold energy. "COLD" is simply the lack of thermal energy.
Okay, write with concerns/questions ... I keep checking to see if you wrote! I will get back to you ASAP.
Thursday 3 April:
This lecture focused upon endothermic and exothermic energy exchanges - and as these terms apply to chemical reactions and physical changes.
First - under natural circumstances, energy flows from high(er) levels to low(er) levels of energy.
Bond breaking absorbs energy and bond making releases energy.
We took another look at applicable potential energy diagrams. Such diagrams are pretty sophisticated - being used in any unit on kinetics (the rate of a reaction).
With that we worked through a number of applications and how we can analyze the energy exchanges in these applications.
I think one of the harder pieces to master deals with physical changes. We must constantly analyze what must be done to the reactant to get to the product when dealing with physical changes.
Thus, we can think about boiling water. Yes, boiled water is hot ... but the question must become what needs to happen to liquid water in order to produce boiled (or vaporizing water).
The answer is we must ADD heat to liquid water. This means that the physical change is best classified as an endothermic energy exchange.
We covered the phenomenon of the sweating glass, air conditioners, freezers, refridgerators.
The most complicated application was a look at the process of perspiration.
First, we must look at perspiration as "dirty" water. And, like any aqueous mixture, the molecules are relatively close to each other (when compared to the vaporized form).
Secondly, we must keep uppermost in our minds that due to our relatively high body temperature (97.4F) we are often the hottest thing in the room.
Thirdly, we are homeothermic organisms (some of us might say, "warm-blooded"). This means that we maintain a relatively constant internal temperature - regulated via various mechanisms.
One such mechanism is perspiring.
Water is released onto our skin - and we - acting as "the stove" heat that water. (Energy moves from high to low).
As that water heats, it turns into a gas - a gas with a greater potential energy. That means that there is a conversion of kinetic (thermal energy) to potential energy. That kinetic or thermal energy is the excess energy building up inside our body. In order to maintain an appropriate internal temperature that excess energy must be lost.
Thus, as our sweat turns to vapor, the heat, from our body is transferred into the perspiration and leaves our body as the vapor dissolves into the air! Viola! We - cool down.
Write me with your thoughts and/or concerns. Enjoy your weekend.
Monday 31 March:
I am quite late - I know - and for those last minute reviewers I am pushing through to post. Time has simply been eaten up by unexpected business.
Assignment:
1) For your Candle Lab Report you need only complete questions 4, 5, 8 (and the objective ...reflection etc). They are in boldface on the last page of the prelab/lab handout.
2) Don't forget your take home is due on Thursday 10 April. You need to "X" your answers. Do NOT just circle answers - if you are someone who circles. You need to "X" per my explanation and directions.
Well I know the change in season is bringing on some tiredness - and I feel for you folks. Work to stay with me in lecture as we are at some of the more interconnecting ideas by now. Frankly, I think you did really well on Monday - tired - but involved, focused.
We made it to page 41 of the notes - but we did a whole lot of chemistry!
I have been focusing upon bonds as of late. These chemical unions between chemical species that represent some level of potential energy.
When a bond is broken, energy must be absorbed, as the bond represents an energy which must be overcome.
The energy absorbed during a period o bond breaking is often represented as ACTIVATION ENERGY. Thus bond breaking is an ENDOTHERMIC process, meaning that more energy must be absorbed.
The source of the energy is most likely from the environment (the air , the water surrounding the reacting chemicals , a Bunsen burner, stove etc....)
When a bond is made, energy must be released -as the the position, the potential energy between the reacting species decreases.
Bond making doesn't have a special name - but it must be an EXOTHERMIC process. More energy is relelased.
When more energy is released than is absorbed - we term the overall reaction to be exothermic.
Now this is a touch confusing - as me must always consider the issue of overall exothermic or endothermic from the point of view of the chemicals - not the environment.
We must consistently ask ourselves what or where is the actual reaction occurring.
During an exothermic CHEMICAL reaction, energy is released into the environment of the air or water. That means the surrounding air or water become(s) warmer.
When more energy is absorbed during bond breaking than is released during bond making, we term the overall reaction to be endothermic!
During an endothermic CHEMICAL reaction, energy is absorbed by the chemicals FROM the environment. Hence, the environment suffers a cooling effect, as energy is drawn out of the environment.
For physical changes we must analyze slightly differently.
Okay - We hit the road tonight running. Write with questions.
Thursday 27 March:
Well, I am a bit later than usual in posting - it has been a busy weekend - but it's Sunday morning and I am ready to go.
Assignments:
1) Poylmer lab report is due on Monday. Be very sure you follow the directives.
2) Your topics for your term paper are due by Monday, 31 March. It is graded . Be aware that I shall not hesitate to tell you that you have gone astray - after your paper is written - if I did not "okay" the topic.
3) We will do the Candle Lab on Monday night. The pre-lab is posted under the Notes tab on this website , and I will have a hard copy for you on Monday.
We are kneedeep into our work on Energy. We are at the top of page 39 in the newest notes packet.
Essentially I am working to draw a line between the concept of potential energy (Big Idea #3) and chemical bond energy.
Potential energy increases with an increase in distance between two chemical species and potential energy is lesser as that distance is decreased.
Whenever a bond is made, energy is released. In order to bond, two species must get closer together.
As a covalent bond is formed, the positive nucleus of one atom attracts the electrons of a second atom. And, the electrons of the first atom are attracted to the positive nucleus of the second atom.
A potential energy exists between the two species. As the bonding process occurs (like shaking hands), the two species must move closer to each other.
As they move closer to each other, the position decreases (This means the potential energy must also decrease).
However, we know from Big Idea #1 that energy is conserved. That decrease in potential energy cannot just disappear.
In fact, that potential energy is CONVERTED to a kinetic energy (in the case of bonding it is often thermal or infrared energy).
This infrared energy is released into the surrounding envirnonment.
Hence bond making releases energy.
The resulting bond does, however, continue to represent a particular amount of potential energy as the bond has a length and a strength.
Short bonds tend to be quite low in potential energy and conversely short bonds tend to be quite strong.
Because the potential energy is so low, it takes a greater input of energy into breaking it - hence a shorter bond tends to be stronger.
Bond breaking absorbs energy - and we will investigate more of that on Monday.
Okay! I think that's it. Write with questions / concerns. I will get back to you ASAP!!!!
Monday 24 March:
Assignments:
1) Your polymer lab report is really a mini-paper. The requirements are listed on the last page of the pre-lab you picked up in lab. If you have lost your copy, you can download or review the work using the link found on the "Notes" tab of this website. You do not need an objective or a reflection. You do need to embed your citations and a works cited. A single page of type at Times New Roman 12 font, should have around 22 to 25 lines of type. (My head is full of stuff you cannot even begin to imagine.)
2) (This isn't really an assignment - just an FYI.) We will perform the candle lab next Monday - not the food chemistry lab. I will give you a copy of the lab in class on Thursday.
Okay, everyone picked up a copy of the notes for the newest unit - Energy!
Here's a re-cap of what I think was a productive evening's work.
Energy is all about the ability to create a change (or to do work).
Two major forms of mechanical energy are potential energy (chemical bond energy is a form of potential energy), and the more familiar kinetic energy (light, microwaves, radiowaves, running, moving, infrared, ultraviolet, singing, sound....)
To help explain the ability to create a change or to do work, I began to discuss muscle contraction. Myosin and actin protein fibers found bundled in sacromeres can slide over each other (there's change in position ) .
We then began to discuss the tiny but effective Ca^+2 bridges between the fibers and the need for K^+1 for the release of the contracted muscle fibers.
All was well and good - and THEN ... and THEN there was that question about grape seed oil - which led to Resveratrol, and its classification of an antioxidant. Hey Tom, what's an antioxidant? .... Oh Goodness.... Grape seed became a wonderful seed for the next 40 minutes of class! (Did you "seed" what I did there?)
I began to discuss the oxidation of Mg in a reaction of O2(g) to produce MgO(s).
Then I heard the crickets chirpping. I became convinced folks were not with me - so I determined that we needed to punt ...
We began with a review of electron configuration. Using the less-than - perfect Bohr model (but appropriate for our purposes), I reviewed that electrons can be organized around the nucleus of an atom, at points of energy possession or quanta.
It is pretty common to state that as a rule, the first level can hold a maximum of 2 e-.
The second level can hold a maximum of 8 e- and so on, per a calculation of 2n^2 where n is the number of the energy level.
So, assuming the 1st energy level, 2(1)^2 equals 2. Hence the max number of electrons is 2.
For the second level 2 (2)^2 equals 8. Hence the max number of electrons is 8.
The other rule to consider is the Octet Rule (or rather the Octet Reasonable Guideline of Sorts). This establishes that the outer most layer of electrons (1 to 7) most probably holds a maximum of 8 electrons.
That is, the outermost energy level of an atom will probably hold 1 to 8 valence electrons. And, as a generally reasonable guideline we can state that atoms tend to react so as to acheive 8 valence electrons or as close to 8 as is possible.
This idea led us to master (and you folks absolutely did master this) the prediction as to whether an atom would lose or gain or share electrons in order to gain stability.
When an atom has fewer than 4 valence electrons it will probably lose those valence electrons and drop back to a completed energy shell.
The atom will become OXIDIZED.
When an atom has more than 4 (as in 5, 6, 7 valence electrons), it will probably gain enough electrons to get to 8.
The atom will become REDUCED.
You see, very often, atoms give up charge neutrality (a charge of 0 when #p = # e-), in order to get to 8 valence electrons.
Atoms will turn into IONS.
This often confers a chemical stability. Chemical stability generally refers to a the unlikelihood that the species will react again.
Na^+1 ion is a very stable chemical species.
O^-2 ion, the oxide ion is a very stable chemical species.
The Noble Gases (except for He) are species which already have 8 valence electrons - Thus, noble gas species tend NOT to make chemical bonds by losing, gaining or sharing electrons. They already have the perfect situation, as it were.
Thus, there is no such compound here on Earth as NeO [neon oxide] as neon does not make bonds and is not found in compounds!
Once we had that down, and with the introduction of LEO says GER (or OIL RIG), we took another run at the chemical reaction between Mg and O2.
I identified Mg as the oxidized species and the atoms of oxygen in O2 as the reduced species.
I then introduced that another term for the reduced species was OXIDANT.
Hence, OXIDANTS are reduced. (Oxidants gain electrons.)
An ANTI-oxidant must thus be the oxidized species.
This applies to resveratrol, and to some extent Vitamin C (but poorly), or curcumin (from tumeric) or anthocyanins (from blueberries), or Co-Q 10, selenium, or betacarotene, or catechins (from green tea) or
glutathione, or lycopene (from tomatoes) or flavanoids (from dark chocolate) ....in that these are all relatively good antioxidants.
These compounds lose electrons to ROS (reactive oxygen species such as O^-1). They become oxidized and in doing so, they protect our proteins, fats, and DNA from the attack of ROS.
Hence, diets high in antioxidants tend to help slow the negative effects of aging. Antioxidants in our diets help to preserve and to protect our vital structural and functional materials from the attack of radicals!!!!!
We didn't get very far with energy - but dang(!) we did a great deal of chemistry!
Be proud of yourselves. Brava! Bravo! A round of applause to each of you.
See you Thursday! Write with any questions / comments / concerns ...
Thursday 13 March:
Assignments:
1) I will be posting midterm grades. Should you have questions, be sure to drop me an email.
2) Read your polymer lab!!!! Be ready for that lab when we return.
We have finished the first note packet ... getting all the way to page 36. Next time we meet we shall begin our work on energy and a little bit more of atomic structure.
Our work encapsulating intensive/extensive properties of matter (in general) -especially - specific heat, and those energy exchange processes (like how a pond freezes) will be on our next test.
Thus, take a few moments to get the notes, to read over the remainder of the packet and/or get in touch with me to discuss issues should you wish to do so!
Okay - per the notes, extensive properties change as the amount of material changes. Mass , volume and the number of molecules are extensive properities ... add more matter, mass changes, volume changes, the number of molecules changes.
Intensive properties can be interpreted essentially as constants - they are properties that do NOT depend upon the amount of matter.
Assuming constant pressure and temperature, intensive properties include melting point, density , a nd normal boiling point. These intensive properties are perfect for helping to identify the compound or element.
Specific heat is the intensive property upon which I chose to focus.
Specific heat is a value which indicates the amount of energy (Joules), required for 1.00 gram of matter to change temperature by 1 degree Celsius (for our work).
For our class, we can stand by the statement : Slow to heat up, slow to cool down and Fast to heat up, fast to cool down.
This surrounds ideas such as lake effect snow, why the swimming pool water is so cold in the morning but so warm at the evening (we did this during a demo of boinling water), aluminum foil's use in cooking etc....
How a pond freezes needs to be studied - but in short, I can tell you that it all surrounds two important ideas.
1) Water is densest at 4 C. It is less dense below 4 C and less dense above 4 C. Hence, really cold water at 4C is DENSER than 2 C water! Yep! Keep that in mind.
2) The entire pond of water will reach a temperature of 4C (layer by layer) as the air cools. Once a layer reaches 4 C it sinks and is replaced until the uppermost layer reaches 4 C. That layer can't sink (as all other layers beneath it are already at the densest ). This uppermost layer continues to cool to 0 C and below and freezing occurs on the surface. AND given our understanding that water expands as it freezes, the increase in volume allows ice to be LESS dense than water - hence ice floats on / in water!
Okay, write me with concerns/questions. Okay? Have a grand break. Stay healthy - I will see you on Monday 24 March. Read the polymer lab....
Monday 10 March:
Assignments:
1) For the Monday we return from break, have your saponification report (questions 3 and 6) completed.
2) DON'T FORGET: Shortly after we return, your TOPICS for your FINAL PAPER need to be emailed to me for review. There are topics on the first page of this website, as well as topics found on the link towards the middle of page 3 of the notes. I have also offered up at least three different ideas in lecture and lab. Get going! Having the topic in on time is graded!
3) Be sure you have handed in all work as I only grade the on-time hard copy of work. Midterm grades are due next week!!!!!!
Sorry that this blog update is a touch late - but I have your chromatography labs graded as well as the first exam (The results are pretty darn good). So those will be coming back to you on Thursday. I shall begin the Analysis of Water grading and maybe have that ready to go as well.
In lecture, we have been going at the dimensions of matter. The dimensions of matter tend to incorporate those measureable or mathematical concepts which discuss the behavior of matter, in terms of phase, density, pressure, mass, volume, weight (when appropriate).
Most of the dimensions of matter have an arithmetic procedure (or multiple equations) which can describe what happens to matter as tempaerature, pressure, volume or mass change.
We are on page 27 - but if we take into account the two demos I did up in the lab room, I could argue that we chipped away at specific heat (page 31). But, we will go over specific heat separately during lecture on Thursday - never fear!!!!!
Now, our course is not about the arithmetic. What we are developgin is an ability and a vocabulary to deal with these behaviors of matter as we continue to study chemical reactions.
These behviors may deal with the compression of a gas volume, or the expansion of a gas volume. They may cover the floating of ice in water, or the change in weight as the gravitational field changes, or why metals don't melt immediately upon heating etc...
This began with an attempt to mesh the influence of pressure on the density of a gas.
In order to get started we did a fast review of density. Class members reported that they felt strong regarding the topic - and that seemed to be so with the first TRY THIS problem we attacked.
Under Pressure (thanks to Bowie and Mercury for a great song)
We moved quickly onto a study of pressure!
Pressure has a similar ratio to that of the density equation. In the case of pressure we discuss not just mass in the numerator, but the product of mass and acceleration. The denominator is area.
Pressure is measured by measuring the impact of a particle with the wall(s) of a container or some other defined, confined boundary.
Assuming we alter only one variable at a time, for our work, pressure of a gas increases with an increase in mass (which can be seen as an increase in the number of molecules, as more molecules translates into more mass), or an increase in acceleration.
Acceleration is going to be very sensitive to changes in temperature. Hence we may infer that hot gases may exert a greater pressure than cooler gases assuming a constant mass and area.
This means - to our everyday world - that we might just need to add air to our tires as winter approaches.
The confined air in a car tire cools as the temperature drops. Hence, the cooler gas exerts a lesser pressure of the tire and the tire "deflates".
By adding more air, we can manipulate the relationship of Pressure = (mass)(acceleration)/Area
by compensating for a decreasing acceleration value by adding a greater mass !!!!
See? We can begin to explain and/or predict the behavior of matter in light of some of the dimensions we measure!
Gases under high pressure, tend to have greater densities than they do under room conditions. This led us to discuss how an aerosal spray can works and why we never throw one into a fire!
Once these concepts had been investigated and one false start (I got stuck in Charles's Law for moment with aerosal cans ... phew!) we introduced the means by which we breathe under normal circumstances.
Hence a quick look at the function of the brain's medulla oblongata with respect to smooth muscle, the diaphragm, rib cage and then the lungs, we could attack the chemistry of breathing as outlined by the work of Robert Boyle.
Boyle's Law tells us that the pressure and volume of a contained gas vary inversely with each other. That means that as the pressure goes UP the volume goes down. Conversely, as the exterted pressure on a gas goes down the volume INCREASES.
Boyle's Law (P1V1 = P2V2) expresses that inverse relationship at constant temperature. That is; assuming P1V1 represents a constant, as P2 drops, V2 must increase (and vice versa) in order to maintain the equality with the other side of the equation, P1V1.
Thus, as the medulla oblongata inervates the diaphragm to drop, the rib cage rises, V2 increases, P2 drops below the value of P1 and air is pushed from higher outside pressure to a lower internal pressure, of the the lungs.
The medulla oblongata reverses the mechanics, allowing the diaphragm to return to normal (rise), the rib cage lowers, P2 of the thoracic cavity increases to a value greater than external pressure, and air is pushed out.
Rinse and Repeat for 100 years or more :-)
We discussed how heavy masses on the chest can interfere with the mechanics and how moving to higher altitudes can lead to High Altitude Sickness (Edema)
Within the context of our work, 2 units for pressure were introduced (the atmosphere or atm & kilopascal or kPa). I tend to use atmospheres when discussing pressure in our course - just a heads up.
We discussed that the atmosphere is in layers and that we live at the bottom of this ocean of air!
This ocean of air exerts approximately 1 atmosphere of presser (14.7 lbs/in^2 or 101.3 kPa) of pressure on us.
The amazing piece is that we push out with an equalizing pressure! Hey! Writing this blog reminds me that I may have one more demo for us!
As we descend into the ocean about 1 atm more is applied per 10 meters of depth.
So naturally, we needed to look at the breaking of a ruler! (See the video link at the bottom of page 24 and show your friends/family and explain it to them!)
Then we took some time out to travel up to the lab where the nature of a liquid's volume was demonstrated to the tune of Twinkle Twinkle Little Star (thank you W A Mozart!).
We then took a minute out to heat/boil some water in a paper cup via a bunsen burner as a demonstration of the high (very high) specific heat of water!
Recall that the specific heat is a value expressing the amount of energy (joules) required to change 1.00 grams of a substance by 1.0 degree Celsisu (or more specifically, 1 Kelvin ... but let's not lose any sleep over this).
Okay! Write with questions and / or issues.
Thursday 6 March:
Class began with a review sheet (see the Everyday Notes tab ), Practice : Concept of Charge. Folks tell me that more of this type of activity is wanted. I will work on a vocabulary piece - and we shall see where that takes us.
Lecture focused upon the Dimensions of Matter. We reviewed the nature of the term, mass, by referring back to the quarter in the cup demonstration and the concept of inertia.
Allow me to state that I was quite impressed by how readily class members relearned / recognized this past work.
On Monday, I may try to get us up to lab early to try a demonstration - especially one regarding volume. Let's see how that can work.
We spent a fair amount of time with the dimension of weight. The definition of weight really surrounds the effect of gravity on a mass. We messed about with the link to the website exporitarium (link at the bottom of page 20) and tried to thread together that mass does not change but weight can as gravity changes.
We also chatted about the misunderstanding of gravity as "pulling us towards a center" as opposed to gravity as the result of the warping of the "fabric" of space-time. And that went pretty well! As one class member said - "It sort of makes sense" . So -okay!
We will pick up with density - just for a bit and then take a look at pressure. With that we shall learn how we breathe!
Okay! We are up to page 21 of the note packet.
LMK what you are thinking . Write me with questions / thoughts.
Monday 3 March:
Assignment:
1) Don't forget that your test is due on Thursday 6 March. If you are absent for any reason, email me a copy of your free responses using MS Word (not Google Docs) and send me a typed list of your multiple choice responses. That stops the clock and gives you some time to get a hard copy into me.
2) For your lab report on Acids/ Bases / Buffers you need to answer questions: 1, 2, 4, 5 and a reflection. Follow the template from the Introductory Packet (page 7). Be sure to cite your research sources by embedding those urls. As a bonus for the test, if you wish, you can answer question #3. There may be 1 or more correct answers. The lab report is due next Monday.
The first half of our lecture was dedicated to the Concept of Charge. The Concept of Charge explains the charge of an ion and teaches us how to interpret that charge. We are on page 19 of the notes.
Hey! Do you know why you can never trust an atom? Because they make everything up! (ba - dup- pum)
Okay, let's begin with a neutral (in charge) atom.
I tried to jumpstart your understanding of the structure of the atom to a metaphor of a castle on a hill, surrounded by a town.
The castle represents the nucleus. In reaction chemistry, the nucleus is stable and does not change in terms of the number of protons.
The surrounding town represents the electrons. In reaction chemistry, the electron number CAN change. That is -roughly speaking - we can add electrons or take them away.
In short, the protons (the atomic number) provides a positive charge, which must be equaled by the number of electrons, giving us a negative charge. The positive charge due to protons and the negative charge given by the electrons must add up to 0, for an atom.
Thus, a proton is assigned a positive charge of +1 and an electron is assigned a negative charge of -1.
Protons are found making up the nucleus while electrons are found in a volume of space beyond the nucleus.
Atoms must have an equal number of protons and electrons.
IONS (and these little devils are the real issue) have an UNEQUAL number of protons and electrons. Ions can be assigned a + charge or a - charge.
Lastly recall that a charge of an ion indicates what subatomic particle is in EXCESS.
Thus, a positive charge indicates that there are more protons than electrons, because electrons were lost by the original atom.
A negaive charge indicates that there are more electrons than protons, because electrons were GAINED by the original atom.
We did a fair amount of practice and we shall do some more on Thursday.
We then segued to our topic of mixture - using petroleum. We lightly discussed drilling vs refining and pretty much put a wrap on the idea of mixtures.
Okay, I think that's it.
Write me with your questions/ concerns / questions .... ! See you Thursday.
Thursday 27 February:
I have a few thoughts on this last lecture session.
1) There was a great deal of chemistry introduced into our conversation. Recall that the overarching idea here is the concept of MIXTURE. With that I have been trying to develop our understanding of just how common and ubiquitous mixtures are in our lives. Acid solutions (a form of homogeneous aqueous solutions) and Basic (alkaline) solutions are important examples.
With that conversation as to what an acidic solution is there came a number of new ideas.
a) The first new concept stated that pure water can break down into H3O^+1 and OH^-1. This occurs to a very small amount, measuring at about 1 x 10^-7 at room temperature. It is from this value that we get our value for the pH of pure water under normal conditions as 7.
This led us to a quick look at the pH scale as expressed by Soren Sorenson's work.
The scale runs from 0 to 14. 7 is neutral (as in pure water ... due to a balance between the H3O^+1 and OH^-1.
A value less than 7 means the solution is acidic.
A value greater than 7 implies the solution is basic (alkaline)
b) An acid is a compound which when added to water INCREASES the concentration of H3O^+1 .
Compounds considered to be acids do this by donating a H+ ion from their structure to water molecules. H2O becomes H3O+1
For the most part, many Arrhenius acids are easy to identify (on paper at least) as they have a formula written with H as the first element: HCl, HI, HF.
Arrhenius acids may be strong (they give up all their H+) or they may be weak (only a fraction of the acid molecules give up a H+
c) The second concept dealt with alkaline or base (basic) solutions. In terms of Arrhenius Theory, a base is any compound which can INCREASE the OH^-1 concentration when added to water.
Classically bases are compounds made from metal species bonded to OH, such as NaOH (Drano), KOH, Ca(OH)2 . Bases can be strong or weak as well.
We briefly discussed how Drano works - by converting fat (lipids, grease) into soap! Per a classmate's question, we found a video that gave a reasonable visual.
d) Organic compounds called alcohols, in which a carbon is bonded to OH (C - O-H ) are NOT alkaline. They ARE NOT considered to be bases.
The OH group does NOT come off when an alochol is mixed into water. The C - OH bond is relatively strong, when added to water. That OH can become reactive - but not by merely dissolving in water.
Conversely the C - H bond that we see in organic compounds does NOT imply the compound is an acid! That C - H bond is TOO STRONG to break when added to water.
So we begin to see differences in chemical activity when metals are bonded to O-H or when Hydrogen is bonded to nonmetal species other than carbon.
Our study of chemistry has begun to take on many layers.
2) My next thought is that I think I shall stop and try a little lesson regarding those positive and negative charges we needed to use while discussing acids and bases.
So our talk re: pretroleum products (especially oil) may need to come at the middle of our next lecture.
Okay - I think I shall end here. I suspect Monday's lecture will help to clear up any remaining confusion - but don't hesitate to write with your thoughts or questions.
See you soon!
Monday 24 February:
Assignment:
1) A take home quest was handed out. Be sure to read the directions. It is due at the start of class on Thursday 6 March.
2) Answer questions 3,4, and 5 for the lab report on the Water Analysis lab. For question 4, be sure to research both chlorine and fluoride. You should develop a rather complete answer which highlights the benefits and the concerns for both. You are then to take a stand as to what you would do should you have control of the situation with respect to their addition to a local water supply.
Well the lab went splendidly folks. I think you each saw a number of chemical reactions - as proven by a few bold color changes and the production of precipitates.
We had a chance to touch upon the colors of fireworks as the colors produced are linked directly to the metal ions we studied in lab. The one exception is the color white. That color tends to be produced by using the actual metallic state of the elements such as titanium, aluminum or magnesium. As these metals burn they tend to produce a bright white light.
As to class we are still puddling through the concept of mixtures.
Class focused briefly upon the breakthrough work of Dr. Kizzmekia Corbett. I was the work of Dr. Corbett and her team which pushed mRNA vaccines forward to the point of useful practicality. She conceived the idea to "wrap" the mRNA in lipids, allowing for the mRNA to survive long enough for our bodies to create and effective response to that mRNA.
We then focused on the vaccine itself. Here are a few points to remember:
1) The vaccine does NOT have virus in it.
2) You CANNOT develop COVID from the vaccine.
3) The vaccine is a mRNA vaccine. This means that the mixture contains the directions (mRNA) to build a single protein of the virus. In the case of the COVID vaccine, those directions were to build the spike protein of the virus (NOT the virus).
As our bodies read and begin to make the spike protein the immunity system comes to the recognition that this protein is foreign and we develop cells to destroy it.
After a week or two, all parts of the vaccine are flushed from our bodies. However, the immunity cells developed to recognize and destroy the spike protein remain in our body. Our bodies are now primed to call up and manufacture an immunity response very, very quickly - and thus, we can defeat an infection of COVID when needed.
As an side, we need boosters to deal with the changing nature of the virus. New (successful) strains of the virus have altered the spike protein (via evolutionary forces). The boosters are designed to account for these changes.
The vaccine is 9 to 11 different compounds mixed together. Hence, vaccines are mixtures of various compounds.
Once done we turned our attention to another application of mixtures - the work of Alice Ball.
Her groundbreaking work regarding an antimicrobial treatment for leprosy in the early decades of the 20th century, is a remarkable story of plant botanical chemistry. Her work impacts our topic in that chaulmoogra oil (a mixture) was successfully separated and manipulated to preserve effective antimicrobial activity via saponification and esterification. Both of these processes are covered in our lab work a bit later in the semester.
Okay! Write with your thoughts or questions. See you all Thursday.
Thursday 20 February:
Well, it certainly was an interesting evening's discussion. We did a great deal of rather sophisticated chemistry as I tried to answer a few questions.
But first - let's review the upcoming assingments.
1) Be sure to prep for Monday's lab re: Analysis of Water. We will test only two samples of water. I will make two samples of fairly awful aqueous solutions. You are welcome to test both of them. However, if you wish to bring in an interesting sample of your own (e.g. from your well), feel free to do so. You can test that and one of the samples I put together.
2) On Monday I will give out the first of your short take home quests. It will cover a fair amount of work and you are welcome to research, use your notes, work in a group. No short answers however, should be identical. You are to create/author your own answers - Yes, work with a friend, but create your own response. We will discuss its due date, when we see each other on Monday.
Okay, we are on page 15 of the notes. As I quipped - we are not getting through the packet quickly - but we are doing a ton of chemistry.
In terms of mixtures we emphasized :
1) Mixtures are physical combinations of substances (element /compounds)
2) Mixtures can be homogeneous or heterogeneous.
3) Mixtures do NOT have definite proportions of ingredients. Think of a toss salad. We can change the amounts of the ingredients at a whim.
4) The components of a mixture can be separated from each other MORE EASILY than the bonded atoms of a compound.
5) We can use chromatography to separate the components of a mixture. We can use filtration (as in making coffee) or boiling away water to separate the pure H2O (distilled water) from the materials dissolved in that water.
6) When materials are dissolved in water we call it an AQUEOUS SOLUTION. Water acts as a solvent.
7) ALLOYS are a mixture - they are NOT an aqueous solution. Rather they are really solutions of metals ... where one metal is merged (dissolved) into the spaces between a second metal.
Now, as an educator, I hate to have a client ask a question and in return find me asking them if I can put their question on hold until we get to that topic. I like to try to answer there and then - and yet I recognize clients may not have a full background . I try to take advantage of that desire to know...
Well last night was such a time. While taking questions about the homework, a classmate asked about molecules and covalent bonds.
Short answer: A covalent bond exists between two nonmetal atoms. A complex of two nonmetal atoms is called a molecule. Hence covalent bonding and molecules are closely associated.
A MUCH LONGER ANSWER:
A bond is considered to be a chemical union , made from electrons, in which a few things can happen. Bonds are often described as a form of potential energy (more on that later ... because there will be some sort of change or work involved)
I will mention two things that might result in terms of a chemical bond.
1) An atom can "take" an electron from a second atom. The loss of a NEGATIVE electron makes the loser into a POSITIVELY CHARGED ion and the atom that "takes" the electron becomes negative.
The opposite charges attract and we say an IONIC BOND has been made. Essentially an ionic bond is due to the attraction of oppositely charged species due to a COMPLETE TRANSFER (taking) of an electron.
We see this type of bond between metal species and nonmetal species.
2) Electrons can be shared. This type of bond is called a COVALENT bond.
Covalent bonds are made when atoms SHARE electrons. Neither atom has the ability to just "take" electrons from another atom. Rather, due to a weaker ability for either atom to "take" and hold onto an electron, many atoms share the electrons.
This sharing of electrons creates the covalent bond.
So assume two atoms A and B. In a covalent bond an electron from atom A is attracted to the nucleus of atom B. Meanwhile an electron from atom B is attracted to the nucleus of atom A.
The sharing may be equal or unequal. For instance, atom "A" may attract the electrons more strongly than atom "B" or they may attract the electrons equally....
This ability to take or share or just to attract electrons of a bond is well explained with the concept of
ELECTRONEGATIVITY.
The Pauling Scale of Electronegativity expresses the tendency to gain an electron of a bond using assigned values which run (roughly) from 0.7 to 4.0.
Fluorine is recognized as having an electronegativity value of (roughly) 4.0. This means that fluorine has an incredibly strong attraction for the electrons of a bond.
Cesium has an electronegtivity value of 0.7. Cesium is going to lose that electron. The low value indicates that cesium has virtually not abillity to snag an electron from some other atom.
When a metal of low electronegtivity reacts with a nonmetal of high electronegativity, the nonmetal tends to "take" the electron. The metal loses the electron, and the nonmetal gains it. This creates positive and negative charges and the two species attract each other, to create an ionic compound via an ionic bond.
When nonmetals react with other nonmetals, they end up sharing electrons as neither nonmetal has a dominating electronegativity value.
This ends up creating a covalent bond. (Hence, covalent bonds are tightly associated with molecules).
See? We are back at the SHORT ANSWER!!!!! But now, there is a "why" to go with it.
I figured I was done - but NOOOOOOOOOO.
Another student asked: Why does alcohol (like ethanol) evaporate so much faster than water?
I took the opportunity to explain this by citing INTERMOLECULAR FORCES OF ATTRACTION.
Short Answer: The molecules of water are strongly attracted to each other. This strong attraction between the molecules takes more energy to separate the molecules into the gaseous phase (to evaporate it).
Molecules of alcohol (ethanol) are NOT as strongly attracted to each other. Thus, it takes far less energy to separate the molecules into the gaseous phase.
A MUCH LONGER ANSWER:
BONDS are stong and exist between atoms or ions.
INTERMOLECULAR FORCES are weaker than bonds and exist between whole molecules, as a rule. (The strongest intermolecular force is about 5% of a certain covalent bond's strength.)
BONDS are like your shoulder joint ... strongly associated with your body.
INTERMOLECULAR FORCES are more like holding hands or walking shoulder to shoulder with someone.
(weaker than a body joint)
INTERMOLECULAR forces evolve AFTER bonds are made.
INTERMOLECULAR FORCES may also be explained using ELECTRONEGATIVITY (No wonder Linus Pauling won the 1954 Nobel Prize in Chemistry...)
Molecules MAY HAVE A PARTIAL DISTRIBUTION OF CHARGE. That means, that parts of a molecule may be PARITALLY possitive (a little positive) and PARTIALLY NEGATIVE (a little negative).
These areas of partial positive /negative attract the partial positive / negative areas of a SECOND or THIRD molecule.
This attraction creates the phases : strong intermolecular forces create a solid, moderately strong intermolecular forces create a liquid phase and weak intermolecular forces create a gaseous phase.
Water molecules (for reasons we did not discuss) have STRONG intermolecular forces between their molecules due to the partial charges on oxygen and hydrogen atoms. It takes a fair amount of energy to turn liquid to gas.
Ethanol however, has much weaker intermolecular forces, as we saw with its molecular structure. Hence, ethanol turns from liquid to gas much more easily as it requires less energy to do so.
See? We are back to the SHORT ANSWER ... but now, with a "why" !!!
Along the way we discussed issues of density.
Why does ice float on water? Why was it lucky for life on Earth for ponds freeze with ice at the top?
We discussed that items of lesser density tend to float in materials of greater density. Thus, icebergs with a density of (on average) 0.917 g/cm^3 will float in saltwater with a density of about
1.0 to 1.03 g/cm^3
Helium balloons float in air and oil floats on top of vinegar ... all due to density differences.
Materials of lesser density float in materials of greater density. Recall that golf ball floating in saltwater from a few weeks back. The golf ball's density is less than the density of the salt water mixture I created. Hence it floated.
Anything which sinks in water (like our aluminum rods from lab) must have a greater density than water.
Okay! Write with questions / issues! I enjoy hearing from you!
Thursday 13 February:
Assignment: Work through some of the problems on pages 13-14 of the notes. The answers are given. Do as many as you feel you need to do - check your answers. Bring in your questions or email me!
Lecture dealt (essentially) with a continued conversation regarding the identification of organic and inorganic compounds.
It included the general idea that organic compounds will have: C - H which means carbon atoms bonded to hydrogen atoms with a covalent bond.
I know we have yet to learn about covalency in bonds, but I am simply trying to get you used to the idea that the dash (as in C - H) represents a special type of bond called a covalent bond. We also touched upon the idea that electrons are shared in a colvaent bond. (Recall I spiral - so I toss out an idea and circle back to it in time at a different level).
We touched upon ionic bonds. An ionic bond is between charged (+ and -) species. The big take away is that we will find ionic bonds in compounds that have a metal bonded to a nonmetal.
This of course brough us back to the use of the Periodic Table of Elements.
We took notes on the term molecule. A molecule is a structure made of nonmetals made from more than one nonmetal bonded to another nonmetal via a covalent bond.
Not all molecule are compounds. CH4(g) is a compound, an organic compound, and a molecule, with/due to its nonmetal composition and covalent bonding.
O2(g) is an element, but has covalent bonding between the atoms of oxygen and is a molecule (because both of the the oxygen atoms are nonmetals).
NaCl(s) is a compound, and inorganic compound but has ionic bonding, due to a metal and a nonmetal.
SO2(g) would be best described as a compound, and inorganic compound, a molecule (due to shared electrons between nonmetal atoms).
It's a fair bit of information - and it sounds as though it overlaps - so let's try it this way:
Nonmetals bonded to each other create a molecule.
Sometimes the molecule is a compound AND sometimes we could end up with a molecule which is an element.
1) If the two nonmetals are DIFFERENT nonmetals then we have a molecule (they are nonmetals) AND a compound (they are different elements).
2) If the two nonmetals are from the SAME element (O2) then we have a molecule AND an element.
3) If there are at least two different nonmetals and some include C bonded to H, then we have a molecule (everything is a nonmetal), AND a compound (the atoms are from different elements) AND it's an organic compound (due to C - H).
4) If there are at least two different nonmetals but a LACK of C bonded to H (like SO2, PH3, CO, H2O ) then we have a molecule (all nonmetals), AND a compound (they are different elements), but probably and inorganic compound as there are no C -H covalent bonding.
5) When there is a metal in the compound, then it's an ionic compound with ionic bonding and an inorganic compound.
Yikes! Recall we can each be described by multiple adjectives - so too can we describe matter.
I think I will leave the recap there. Note the use of terms. Be familiar with the vocabulary:
- element
- compound
- organic compound
- inorganic compound
- ionic bond (more later)
- ionic compound
- molecule
- covalvent bond
Write with your questions. PHEW!
Monday 10 February:
Assignment: 1) For you Chromatography lab be sure to answer questions 1, 5, 6 a and b from the lab manual and the application question re: blood panels. The entire assignment is on your pre-lab. You have a hard-copy of that and it is on this website under the first tab, as well. Turn your report in next class (We have Monday off). Be sure that data table is made with MS Word, Excel or some other program. No hand-drawn tables!
Assignment: 2) For those offered a chance to re-write their Alchemy lab report, email me the completed report. I will scan it over for the necessary changes. I hope this will save you the cost/effort of reprinting the entire lab for just one question or so. Those changes should reach me by Thursday 13 February. This is a one-time deal ;-)
I think you can now see how I grade - via comments (!). This is one reason why I want hard copies of your work. I want to interact with your work - dialogue with you. If you can't read my ancient hieroglyphics - see me - ask a question. With the exception of emailing the Alchemy re-write, keep the hard copies coming in.
****************************
Well another lab down and your work looked terrific. You were safety conscious (everyone had their goggles on). People worked well together. You took on the challenge of that data table beautifully! It was great!
Remember, the chemical dyes looked old - so in case of a poor correlation between your standard tests (the knowns), and your unknowns - don't worry.
Your job is to disscuss that disconnect - mention it - try to explain it or suggest an improvement. The learning is in the thinking - not just the "right answer".
The lecture did not see us move very far into the notes - but I felt that, class members believed the conversation which did evolve was worth having.
You need to let me know if I am wrong or right on that feeling. We sort of went down a number of rabbit hole as we worked through a bunch of complex (and strong) questions.
Has anyone else begun to see that we are spinning webs, interconnecting threads? We have, to my mind, begun to network information - resulting in knowledge.
Frankly folks - those questions were wonderful. It is great to have you stop me and ask to repeat something. It is wonderful for you to ask about a topic that is in your head. I have an idea of what I want to get through - but I am working to blend into that idea, the pieces you want/think about. Keep that kind of; respectful, positive, engaged behavior going! Bravo/Brava!
We are on page 10 to 11 of the notes.
Now, for those folks not in attendance, you may wish to ask a neighbor for their notes - as many things written down in class were not found directly in the notes. The applications of NaI, complete combustion, the purpose of a car's carburetor, the hormone thyroxine, goiter, iodized salt etc...may prove interesting.
We began with a review of subtances (elements / compounds) and mixtures.
There was a review of the metaphor of a mixture as a sentence, made of words and letters (compounds and elements) in a non-definite proportion.
We reviewed homogeneous and heterogeneous.
We then made our way into some awful definitions re: inorganic compounds and organic compounds.
Allow me to approach the topic a bit differently. I am going to simplify it a bit and I will begin with organic compounds this time.
An organic compound will have carbon bonded to hydrogen ( C - H ) via covalent bonds (electrons are shared) or be some sort of derivative of that. I will explain the idea of the derivative later on Thursday (should the snow allow!).
So, organic compounds are:
1) Compounds: There are two or more different elements in a definite proportion .
2) Two of the elements making up the compound will be (as a rule for our classwork) CARBON BONDED TO HYDROGEN.
C and H may be the ONLY elements: CH4(g) methane (a.k.a natural gas).
There may be atoms of OTHER elements as well (e.g. O, N, Cl, F, S, Br) BUT for our work there will be C - H somewhere in the structure.
The line ( - ) between the C - H represents a covalent bond (shared electrons). Know This!
For instance we can take a look at glucose (C6H12O6). Notice there are many C-H bonds as well as O-H bonds or C-O-H bonding. The presence of the C-H bonds are what make this an organic compound!
I think that is something you should memorize.
Organic compounds can undergo a number of chemical reactions.
Two important examples are Complete Combustion and Incomplete Combustion.
Complete combustion is pretty much what happens in terms of a fire or what goes on in your house furnace (assuming you don't have electric heat)
In a complete combustion reaction an organic compound is reacted with enough oxygen gas to produce carbon dioxide, water and lots of released energy.
For example: CH4(g) + 2 O2(g) --> CO2(g) + 2 H2O(g) + kilojoules of energy
Complete combustion produces carbon dioxide and water. Memorize this!
Incomplete combustion occurs in a smoldering pile of embers or the internal combustion engine of a car. In this reaction, oxygen is limited and carbon monoxide (not carbon dioxide) is produced along with water and a limited amount of energy.
We discussed types of furnaces in our homes, ranging from oil burning furnaces to natural gas forced air furnaces to electric heat, steam heat etc.
By the way - If I remember I am going to bring in my copy of McPhee's Encounters with the Archdruid and read you that first paragraph about the mountain cabin.
Inorganic compounds are compounds (2 or more different elements in a definite proportion) BUT they LACK C - H covalent bonds.
Many of these inorganic compounds may be further classified as salts (for example). A salt is produced when an acid reacts with a base (more later).
The most well known salt is TABLE SALT or sodium chloride NaCl(s).
There are no C - H bonds in NaCl . Hence, NaCl(s) is an INorganic compound.
CO2(g) is an inorganic compound (NO C-H bonds)
H2O2(l) is an inorganic compound (No C-H bonds)
So, for our class, Organic Compounds will have at least , C - H and Inorganic Compounds will NOT have
C - H covalent bonds.
You can tell what something is - by what it is NOT!
Yes, there are exceptions - but we are not going to need to worry about them. Learn the above recognition skills (as they are not so much definitions as recognition skills). Those skills will serve you pretty darn well.
We then discussed iodized salt working off of a question from a class member.
Iodized salt is a MIXTURE of NaCl and NaI.
The NaI is added to NaCl to supplement our intake of iodide (a negative or reduced form of iodine atom)
so that the hormone thyroxine is produced.
We discussed the position and purpose of the thyroid gland as well as the requirement for iodide to make thyroxine.
The absence of iodide can create a goiter, hypothyroidism and hyperthyroidism.
Iodized salt is quite common in the supermarkets of the East Coast of the USA as our soil is lacking iodide. Thus, the fruits and vegetables grown here have a lesser concentration of the necessary iodide nutrient/mineral. The US government first sanctioned the use of iodized salt (mixture) way back in the 1920s. (No, I do not recall them doing it.)
It was the Chinese who were first to note that goiters decreased in size with an increased intake in seaweed. Seaweed happens to be high in iodine! See the NIH at: https://pmc.ncbi.nlm.nih.gov/articles/PMC3509517/
Okay! That's the short version! Holy Heck - I thought lecture was quite far reaching. Let me know what you think.
Write with questions/concerns.
Monday: 3 February: You did so very well on that darn density lab! Let me tell you what I saw:
I saw you stay focused during the pre-lab and I think you really tried to master the vernier calipher. Your measurements prove it!
Did you pick up as to the consistency that existed between the volume calculated with measurements from the vernier caliper and the volume obtained from the graduated cylinder? Couple that to the fact that your values for density were really good. You were fire! Bravo and Brava!
Assignment: For your density lab report, be sure to follow the template I gave you, and be sure to complete questions 1, 3 and 4 in the green lab manual. Be sure to answer question 1 using your AVERAGE VALUES! Don't forget your reflection. I am going to really look at it for how you handled the challenge of the vernier caliper. (What made you so successful / gave you heart ache?) . Staple your data tables with your averages to your report.
If you gave me a "hard-copy" of your alchemy labs , I have graded them up. I shall give them back to you on Thursday.
Some of you were Mary Poppins ... Practically Perfect People (or at least your work was practically perfect). Many of you are invited to fix some of the pieces that are missing. Some forgot the reflection, others forgot the alloy question found on the pre-lab.
Virtually everyone cited their sources. Abso-freaking-lutely Fabulous! It is so good to see.
I offer a re-write for this first lab only, in simple recognition that it is your first attempt. So we shall discuss this in class on Thursday.
As to class, we put a wrap (for now) on Big Idea #1 LCME (Law of the Conservation of Matter and Energy).
We then attacked the classifications chemists use for matter.
We are up to page 9 of the notes.
There are SUBSTANCES & MIXTURES. Matter is generally going to be one or the other.
Substances are either elements or compounds . I spent a fair amount of time trying to get you to recognize when you are looking at an element or compound, when reading/researching articles.
A symbol made with only one type of capital letter is going to be read as being an elemental substance.
O2(gas), Na(solid), etc.
The atoms of an element all share a common atomic number (or, they all have the same number of protons in their nucleus).
I divide the elements into 4 categories, loosely based upon what they do with their electrons.
Metals or Metallic elements tend to lose electrons to other non-metal atoms.
Nonmetals tend to gain electrons from atoms which hold onto their electrons more weakly (very often metals).
Metalloids can do a little bit of everything. We don't work very often with metalloids as they are a funky collection that even have chemists arguing.
Noble Gases don't really lose or gain their electrons. There a a few minor exceptions - but the big picture is that they have all the electrons needed and these elements tend NOT to make compounds.
A symbol made with two or more DIFFERENT capital letters in a strict ratio will be read as being a compound substance. Examples are compounds like H2O(liquid), or C6H12O6 (solid)
Recall that comound substances (or just compounds) can be decomposed into simpler substances and have chemical bonds (a form of potential energy) between the species that comprise the compound.
The elements that make up a compound tend to lose their individual properties/identities.
To use the metaphor I was developing in class:
An element is like a LETTER of the alphabet: whole and unique
A compound is like a WORD. There is a fixed ratio between the letters (elements) . Change a letter (element) and you change the compound.
Mixtures are the most common experience for us. They are physical combinations of substances.
A mixture are like a sentence - any number of letters and/or words strung together physically. The number of words can be changed.
Today I have been thinking that to better grasp what I mean by a physical combination - we should touch on what we mean by a chemical reaction. You can know what something is, by what it isn't.
So I may just attack that issue on Thursday.
Okay, I feel that's it. Write with questions. I will see you Thursday. It was a very good Monday. Stay safe out on the roads come Thursday - there will be some snow.
Thursday, 30 January: Well we are well into the first note packet. I needed to jump around a touch only to help prep us for Monday's lab on measurement and density.
First, a little housekeeping:
1) Two assignments are due on Monday:
a) Your lab report for your Alchemy Lab is due. The template for writing a report is in the introductory packet. There are three questions to answer: Questions 1 and 2 from the green lab manual and the third question regarding alloys in history (found in the prelab I handed out ,and you can find it here on this site if you need to do so). You need to cite your sources for question 2 - so don't forget. There is also a reflection to write. Recall that the reflection is about the interior dialogue you had during the lab and/or the conversations you had with a partner. What made you successful? What don't you understand? What allowed you to get through the experience successfully, or what held you back?
b) Your 5 questions piece. This does not need to be grand. I would like to know some questions you might have so I can build pieces into the course.
Okay, on to the lecture.
We focused upon two concepts
1) Big Idea #1: The Law of the Conservation of Matter (Energy and Charge)
2) Matter has dimensions - measurable qualitites such as; Mass vs. Volume and Density
The Law of the Conservation fo Matter, Energy and Charge surrounds a basic idea in chemistry.
You cannot get out what you did not put in.
You cannot get out MORE than you put in.
You cannot get out LESS than you put in.
Matter (energy and charge) cannot simply disappear via reaction chemistry activities. Each is conserved.
Matter may change phase (turn from a solid to a gas, or new bonds may be made between atoms givng us new compounds). But the total amount of matter does not change.
Energy may convert from mechanical to infrared and be transferred (Recall rubbing our hands together and then putting them to our faces.).
We are going to see this Big Idea over and over again throughout the course.
That conversation brought us to page 6 of the notes.
We then hopped over to page 22 of the notes to discuss mass, volume and especially density.
Density is the compactedness of matter. Density is a ratio (a direct proportion) between mass and volume.
Under constant tempereature and pressure, as mass increases, so too must the volume of the sample increase.
They scale with each other - hence density becomes a constant. As we (hopefully) will see in lab, the density of a long rod of aluminum metal will have the same density as a small rod of aluminum metal.
Sure the longer rod is more massive - but it also has more volume when compared to the smaller rod.
Hence the density should be the same.
Now mass is a tough idea to define. I attacked the definition with a demonstration of what might be termed inertial mass. (That was the coin in the cup demo.) I compared the quarter to the jar of pennies.
It was much too difficult to sweep the cardboard out from under the jar of pennies - hence the jar of pennise was more massive relative to the quarter.
With this work regarding the concept of MASS, I took a fair amount of time to differentiate between mass and WEIGHT.
WEIGHT is concerened with mass in a gravitational field. The word weight and mass seem to be interchangeable but that is only because the gravitational field on Earth is relatively similar wherever you are. There are some hiccups as at the equator, the poles , in Death Valley or atop the Himalaya Mountain range. But for most of us, the gravitational field pushing us down (hmmmmm) is not terribly different from place to place.
However, weight and mass are not really the same thing. When we go to the Moon, our mass is constant but our weight is less because the gravitational field of the Moon is 1/6 that of the Earth's. Hence, the muscles built here on Earth can do amazing things on the Moon - for a while, at least. (Things change ... "da-da-da-ta" ... more to come later!!!!!!
We then did a little density demonstration. (The golf ball in the graduated cylinder). The gold ball only sank so far - because a mixture of GREATER density (saltwater) was at the bottom of the cylinder.
Okay - Monday gets us a little story about a famous power couple of the 1700s and moves us into an introduction regarding the types or categories of matter.
Write with any questions! You did really, really well in class - you were engaged and focused. Bravo and Brava!!!!
Monday, 27 January :
We began lecture and made it up to page 5 of the notes.
The main theme of the evening was on differentiating between matter and energy.
We began however, with a look at the definitions of science and then of chemistry.
Science is a process - not just information. Science is the process of constructing understanding of the the universe. We need data, facts, the information - but science weaves information into knowledge - something used to make predictions or to further explanations.
I grant you that focusing on such a definition may seen a bit different - but it may help you to grasp what I want to do with our time in class. I want to move you away from simply memorizing facts (don't become a telephone book) to using information to build ideas/understanding of the universe.
As an aside - don't get upset when "science" tells you something has changed. Science hasn't lied to you - it has simply refined its process and learned something new. Science is dynamic - it's all about life long learning.
I want you to be part of that dynamism! I am expecting you to think! To construct understanding. That's a pretty big goal.
If you recall the notes - You and I ARE the universe, expressing itself as human for a time. We are the stuff of stars, the stuff of ancient, ancient matter and energy.
With that, we took a minute to see that chemistry deals with matter in terms of its properties & composition. The reactions (changes) matter undergoes , and the energy associated with those changes.
We spoke a bit about reaction chemistry (all about those electrons) and nuclear chemistry (surrounding the protons and neutrons).
This led us to taking a long look at matter - anything with a mass and volume. (A fascinating - but more advanced question - is asking why matter has volume ... why do we or any type of matter take up space? That answer is found in the Pauli Exclusion Principle!!! More later)
However, when I was a student I found that idea of mass and volume a touch "out there". I couldn't wrap my mind around it's true implication - so I offered everyone a metaphor.
Matter is anything we can put into and keep (for a reasonable time period) in a balloon. As I said, all metaphors fail at some point - but I like that idea of matter and balloon. It's a good initial metaphor of what we mean by mass and volume.
Using a balloon I can imagine more matter means a greater volume (the balloon stretching into space) and a greater mass. I stopped for a second to just to mention that mass and weight are not really identical - more on that later.
Anything which is not matter, is probably energy - as we can know what something is, by what it is not!
Energy is the ability to create a change or to do work.
Work is that whole thing about force and distance (W = F x d). I threw a pen ... or even better, for our HPX majors ... how muscle contraction can be used as an example of work (energy), by allowing actin and myosin fibers to slide or move over each other. Energy was used to manage that change in position.
Excercising uses energy!
I like the bit about creating a change. I can understand that much better with ideas like photosynthesis, where sunlight (the energy) creates a change in the structure of carbon dioxide and water to produce glucose.
Now, while working to develop a grasp of matter as having mass and volume we took a side road into the work of Einstein.
And I sort of feel that side road can be valuable. As I said in class - we could look at matter as highly, insanely, organized energy. It's a neat idea - but not very practicle for first year students. So we worked away at trying to understand that, in chemistry, we sort of divide up matter and energy.
Another side road took us into the composition of the atmosphere.
We live at the bottom of an ocean of air! (Hmmmm)
That ocean of air is approximately 78% nitrogen gas, 21% oxygen gas with the remaining 1% made up of gases like carbon dioixde, carbon monoxide, helium, sulfer dioxide etc...
We inhale this ocean and we exhale some slightly different version of it. We use some of the oxygen we breathe in but our exhaled breath is still running at approximately 18%!!!!! (Remember .... mouth to mouth resuscitation!)
We wrapped up class with a little closure and we developed a list of some of the more salient pieces from the class . Ihope this blog reinforces some of that learning.
Remember ... Tell them what you're going to say. Say it. Tell them what you said. This works for class presentations, teaching, speeches - all sorts of things.
Lab went really well. Each of you were marvellous!!!!!!
It was a long night - full of safety rules, pre-lab, maybe some anxiety - and everyone handled it with grace and aplomb! (That's really old man-speak for - "You folks were jake" ... which is just old man speak for "You folks were cool" ....which really means "You did really well - be proud of yourselves")
Okay, write with questions and/or concerns. I will check my email periodically.
I look forward to seeing each of you on Thursday!
23 January: First Evening of Class!
Assignments:
1) Our first laboratory is next Monday evening (27 Jan). Read the introduction in your lab manual . In the introduction you will find the objective of the lab. You need this for your lab report.
However, the pre-lab lecture notes, the actual procedure we will use and the lab write up requirements are found in this document: Alchemy Lab (click here to open). You have a hard copy in your possession already. I am providing the link for your convenience if you need to get another copy.
BTW: I will have pennies for you. There is no need to bring in your own pennies. During lab I will get you goggles and we will also go over the safety rules for lab and sign off on the introductory packet.
2) Complete the assignment Five Questions (click here). This is due on Monday 3 February 2025 at the start of lecture. You have a hard copy in your possession - but I am providing a link nonetheless.
Now, onto class.
You were asked to pick up a copy of everything from the front desk. You have a copy of;
1) the Unit 1 Part 1 Note Packet
2) a periodic table of the elements
3) the Introductory Packet with the dates / procedures and expectations of the course
4) your lab manual
5) a copy of the alchemy lab (We do a slightly different prodcedure)
6) an assignment called the Five Questions
If you failed to get these artifacts or were you to lose something, you can find digital copies of 5 of the 6 on this website (either under the first tab, or under this blog tab). See me regarding a missing lab manual.
In class we went through the introductory packet. A number of points were highlighted. This number indludes, but is not limited to:
1) this website and its use/organization
2) this course being a writing intensive course
3) the importance to be in attendance
4) the importance of the laboratory program
5) how to remediate missed classes when the day goes wrong
6) the importance of citation of source materials
7) grading
8) important dates
Okay - not much more to add. Timliness to class matters - so get in as soon as you can. My thoughts on this is that you would not be late for a lawyer or doctor's appointment if at all possible - so don't be late for your own education - treat yourself that well.
You can find me in our classroom most evenings before class - take the opportunity to drop in. Treat this like unofficial office hours. Come in, chat about class or tennis or art or cars or whatever might be on your mind.
Drop me an email with any questions. I look forward to seeing you Monday evening.