Sunday, September 29, 2013

Week 3: Hot Pots and Lewis Dots

This week was kind of split into two parts. The first part was focused on the test we took Wednesday. The second part we started on some new material, which I greatly appreciated.
To be blunt, I did very poorly on the test. In hindsight, I should've practiced more for the short response than I did for the multiple choice, because even if I didn't have a calculator I felt I knew the concepts well enough. But for the short response I had severe technical difficulties. This is a problem that I need to work hard to address. But I thought the Hot Pot quizzes were very helpful with the multiple choice section. I'd like to have more of those before tests in the future.
I must admit that I jumped for joy when Dr. Finnan said that there wouldn't really be any math on the next test.
For the remainder of the week, we began doing Lewis dot diagrams which I think are really cute and fun to draw. These are diagrams that show how many valence electrons any given atom has and you can put them together to form molecules. Here is the diagram for water, which I think looks rather like two tie fighters circling the Death Star.
This shows that one atom of oxygen has 6 valence electrons and can thus form bonds with two hydrogen atoms (which have 1 valence electron each). The dots stand for valence electrons. The dashes that you can see are just an easier way to write two dots shared between a pair of atoms. 
Another new thing we discussed was the "octet rule" which basically states that each atom's greatest life ambition is to have 8 valence electrons and will drop or gain electrons in order to do so. This doesn't apply to all elements though, such as hydrogen, which follows a similar "duet rule". 
I think the most confusing thing for most people right now is probably understanding the difference between valence electrons and total electrons. I imagine that in the next few days this will no longer be a problem. 
Rumor has it that we will have a lab next week, which I am incredibly excited for given how entertaining the last one was. I'll leave you all with your science meme of the week. 

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