Assignment: 19 November: Complete the questions found on pages 88-90
Tonight in Class: Lecture was all about types of bonds. It covered the work assigned on Monday 12 November.
At the front of class, I spoke to the final paper. It must be at least 6 pages long, have a font equivalent to Times New Roman 12, 0.5 to 1.0 inch margins, and a works cited page. You must embed your citations as you go. Please refer to the information packet of the first night.
The paper is to demonstrate your mastery of the ideas covered in this class. Your paper is not really a scholarly piece about the topic .... but your proof as to how this class has changed your ability to read/evaluate/interpret chemical information.
You must get your topic "okay-ed" by me in advance of turning it in. I consider this part of the grade.
I diverged from the main topic by explaining how sweating (perspiring) is a cooling action. We hare a homeothermic species .... Our bodies maintain a reasonably constant internal temperature. To that end, you must understand 3 things;
1) often we are the hottest thing in the environment
2) salty / dirty water requires more energy to evaporate than pure water
3) As perspiration evaporates from aqueous solution to gas, it increases in potential energy
Hence, as we exercise (for instance) we begin to generate excess heat. Our bodies deposit salty water onto our skin. Since we are the hottest thing around, the energy to evaporate that solution, comes from our bodies .... Thus we lose the energy used to evaporate sweat, and we maintain a consistent temperature range.
We also discussed hypothermia as well as sunstroke / heatstroke.
Beyond this, in the lecture portion of the class, I tried to develop a set of methods which could be used to identify types of bonds. The lecture followed the information in the two videos and the notes.
You need to be able to identify the type of bond found in a compound or diatomic element. It is testable material. (I am writing that test, now!!!!!! The test will cover electron configuration and Unit 3)
The information is contained within the notes, in fairly sold specificity. Vocabulary is important.
Ionic bonds , transfer of electrons and ionic compounds are linked
Covalent bonds, shared electrons and the term molecules are linked.
We spent a good amount of time discussing that 1 covalent bond is made via 1 pair of electrons (or 2 different electrons)
We then went into reasonable depth on polar covalent bonds and nonpolar covalent bonds ... It is all in the notes!
We began our work on inorganic and organic compounds. Organic compounds are easily identified on a test, or in an article, when the symbol for Carbon is the first listed in the formula. There are exceptions, such as CO2
Okay ... Write with ideas/ questions / concerns .... Get going!!!!! We have 2 more classes, before we close down for the holiday and the rest of the semester .
Assignment: 16 November: Be sure to watch the videos on page 78. Then complete the readings and notes up through page 86. You do NOT need to do the questions on page 86.
Tonight In class: I tried to develop a number of recognition skills and to connect these skills to small sections of the electrochemistry lab.
We spent a fair amount of time on exothermic and endothermic chemical reactions and physical changes.
In short, an exothermic reaction (or change) will have the kilojoules representing the change in energy on the product side of the equation, and an endothermic reaction (or change) will have the kilojoules representing the energy change on the reactant side of the equation.
Beyond recognition skills, the primary idea to be learned dealt with the changes in the chemicals relative to the environment in which the reaction or change occurs.
First, the air or a water are considered to be the environment.... and not really the "chemicals" per se. That is, when chemicals burn, they tend to burn in the air, and that burning affects that environment's temperature. When chemicals react in water, that activity can affect the temperature of the surrounding water.
So, when an exothermic reaction occurs in water or air, the chemicals release energy to the water or air. Thus, the temperature of the water, or air, increases.
When an endothermic reaction occurs in water or air, the chemicals absorb energy OUT of (or FROM) the water or air. This energy absorption helps drive the reaction .... Since the water or air are losing energy to the reacting chemicals, the temperature of that water or air, must decrease.
The second "big idea" developed the recognition skill for ionic, covalent and metallic bonds. Using their copy of the periodic table, which identifies the elements as metals or nonmetals, students were encourage to predict, the type of bond which exists between certain elements.
For instance, in carbon monoxide (CO), since both elements are nonmetals, we can predict with relative assuredness that the bond is some type of covalent bond. (covalent bonds are typically between nonmetal atoms). Covalent bonds exist when electrons are shared between chemical species.
In the compound NaCl, we can see a metal (ion) is bonded to a nonmetal (ion). Since the compound is made from a metal and nonmetal we can predict with some reliability that the bond is an ionic bond.
Ionic bonds exist due to a complete transfer of electrons.
Class members used their copies of the periodic table to determine whether an element was a metal or nonmetal. Using this system of identification (found on page 77 and later in more detail on page 85) we can reasonably identify the type of bond(s) for a fairly large number of compounds.
The system is not perfect. Exceptions exist. As the readings state, bonding is a continuum and very few bonds are completely void of some type of ionic character (due to some level of electron transfer or loss to another species ... even if the bond is ultimately classified as covalent).
For: 12 November: Complete the notes up to and including page 77.
Tonight: We are knee deep into bonding and types of bonds. Two new ideas were introduced on Tuesday (9 Nov).
They are summarized here:
The questions with which we dealt were: "How do bonds form?" and "Why do bonds form?"
1) A general set of mechanisms by which bonds tend to form deal with the attractions between positives and negatives. An ionic bond is an attraction of oppositely charged ions ... It deals with the attraction between a fully positive ion (cation) attracting a fully negative ion (anion). Covalent bonding, involves an attraction of one species electron cloud for the nuclear charge of a second species, and an attraction of the electron cloud of that second species, for the nuclear charge of the first species. This results in a sharing of electrons, an overlap of electron clouds, between two species.
2) Why bonds form (or why chemical reactions tend to result in new bonds being made) was a more complicated discussion dealing with a tendency to lower enthalpy and to increase entropy. Not all chemical reactions follow this pattern of lower enthalpy and increased entropy however. We discussed variations of this phenomenon. This led us to the introduction of the terms, exothermic and endothermic.
Students were charged with familiarizing themselves with the information / notes up through page 77, per the above assignment.
2 November: Assignment: Get Unit 3 read up through page 69.
Tonight we completed Unit 2. An important idea for tonight's work was that you can recognize a ground state configuration as it is the one written on your periodic tables. The excited state configuration will be some variation of that ground state (It will have the same number of electrons, but an inner electron will be raised to a higher energy level, temporarily).
The big idea of tonight's work however, was a review of the origin of light and how it connects to the excited state and ground state configurations.
In our attempt to connect the work to "everyday issues" we applied "blue blood" to the spectrum.
We then began Unit 3. Students are charged with completing the work assigned due for Thursday.
29 October: Assignment: page 63 problems and soap reading
29 October: Assignment: Take Home due!
14 Sept: Assignment: Complete the reading on pages 10-12 regarding Covid Chemistry. Answer the 7 questions on page 12. Cut and paste the questions into a Word document and plug away at your responses. This is a significant assignment. You will NOT know everything in the readings. You do NOT know about electron, or hydrogen bonding or compounds .... I get that. I am trying, to jump start your research abilities. I am here to help. You are not alone in any of this. Write me ... tell me the challenges you are facing , and let's see if I can help. Email me your answers.... Be sure to cite anything you need to look up. It doesn't matter if you have a dozen citations ... That's cool. Okay.... Get working.
3 September: Have your notes up to page 9 . I will publish the alchemy video and notes as well ... Give me a day!
31 August: Have pages 1-6 of the notes completed /filled in. Also, be sure to email me your 5 curious issues by class. I have linked the assignment: First Assignment: Curious