Monday, November15, 2010

11/15/2010

Announcements:

-Test will be on Wednesday after thanksgiving break.

-Web assigns are due Tuesday after thanksgiving break.

-Mr. Paek said he will not return our quizzes, but we get to retake one and drop the lowest.

-Mr. Paek also said that if there is anyone who doesn't get the lewis structure, they should go see him ASAP because it's important. The lewis structure is a key concept and you have to completely get it in order to understand upcoming lessons.

Homework:

-Finish up to page 19.

- Make sure you finish the 2 practice sheets we got on Thursday that go along with the chem think.(they might be collected tomorrow.)

In Class:

Well first Mr. Paek introduced to us the concept of VSEPR. He said that he will use this term a lot and he wants us to understand it. here is what each letter stand for:

-V= Valence

-S= Shell

-E= Electron

-P= Pair

-R= Repulsion

-This theory is used to prove that electron want to repel as far away from each other as possible.

-there are 5 types of molecular shapes: linear, bent, trigonal planar, trigonal pyramid, tetrahedral.

*Linear and bent are usually associated with 2 electrons and are are usually 2 dimensioned . (example by Mr. paek: If Mac and Kevin were to have a fight where would they go in the room to be as far away from each other as possible? the answer was in the corners of the room.)

*Trigonal planar, trigonal pyramid, and tetrahedral are associated with 3 electrons and are usually 3 dimensioned.(example by Mr. paek: if Max, Kevin, and Jimmy were to fight over kinga, where would they want to be in the room in order to be as far away from each other as possible? the answer was 2 would be in each corner and one would be in the middle)

- those were examples to help us visualize and help us understand what molecular shapes look like.

-Other key things to remember is that the lone pairs are key because they push everything down and change shape. And for shape you don't need dots unlike lewis structure.

- The picture at the right is page 16: I am going to go over the first one, so you guys get an idea on what we did today.

CS2

Needs: 24; Has:16;Shares:8; Bonds:4 .

I am sure we all know how to draw the lewis structure for this one ( see Mr. Paek if you don't), well the molecular shape is the same as the lewis structure but without the dots. and the name of the shape is linear.

The next scriber will be Andrea.