Thursday, March 3

We started off the day by making fun of Tim and his inability to speak because he had food in his mouth, which Mr. H does not like in the classroom. We then took out our packets and Mr. H gave us the answers to the reading sheet 7.3. The answers are as follows:

1. ADE
2. False; it is nonpolar, e- are shared equally
3. A
4. C
5. a.) H-F b.) H-F c.) H-O
6. C
7. ABC
8. A
9. a.) Cl-Cl b.) C-N c.) C-O d.) H-O
10. -
11. C
12. If a diatomic molecule has a polar bond, then it is polar.
13. ABC
14. BC, IO
15. B
16. C
17. The polarity of the bonds and the molecular geometry.
18. ADE,

*Mr. H added AX5, AX6, AX2E3, & AX4E2. These will be important for a later time in this blog.

After that, Mr. H reviewed the basics of polarity and went over Tim's blog. After that, he reminded us about the pop quiz tomorrow, Friday, March 4. It will cover the basics of ionic and covalent bonds, the Lewis structure, and the molecular ge

ometry. You will have to memorize the numbers corresponding with the type of geometry the molecule h

as, but Mr. H will provide us the names. It will be multiple choice, along with some Lewis structure drawings and the molecular geometry.

We then turned to the other packet that Mr. H gave to us on Tuesday, and worked on SO2. Like always, you would count the number of valence electrons, do the skeleton structure, and do trial and error. When you have the right Lewis structure, you will then imagine the shape of the molecules without looking it up in the packet. We then did numbers 11 & 13. The answer to number 12 is: 3; 2; 1; Trigonal planar; Bent; 120 degrees. These types of questions will be on the pop quiz.

We then turned back to pages 25, 26, and 10 in our main packet. This will be on the test, not pop quiz. Mr. H explained to us that on the electronegativity chart (page 10), F, which is on the top right corner has a high electronegativity. This means that it is very greedy this its electrons. On the contrary, Fr has a low electronegativity, which is located on the lower left corner. Let's have Cl and Na. One would take the numbers for both elements on the electronegativity and then subtract it. If the difference is greater than 1.7, the elements would just give an electron away, which is an ionic bond. However, if you take Cl and H, Cl and H can share because the difference is less than 1.7. But, Cl would get partial charge. The elements would not share the electrons equally. This is called polar covalent bonding. Number 8 on the reading sheet (7.3, page 25)shows the difference between each element bond. The electronegativity chart shows how polar or non polar an element is.

Number 13 shows this: H -------->Cl. The arrow points over to the element that the majority of the electrons are getting pulled. The greater the number in the electronegativity, the more electrons an element pulls. Cl, has a high number than H, resulting in more electrons towards itself. It is greedy. These are called dipoles. We then turned our attention to the top of page 26, where we take notes on the class discussions. It says, "Some molecules have polar bonds but are overall non-polar molecules." Mr. H explained this idea with the example of SF6. SF6 has F atoms that are opposite of each other in the molecular geometry. On one side, the electrons will pull, but on the other side, it will pull the opposite directions, leading to the cancelling each other's polar bonds. this would make it so that it is non-polar. Same with XeCl2. Non-polar molecules are mostly gases. H2O is bent, so it is polar. Always go to the molecular geometry to determine if this idea is used for that molecule.

We turned our attention to number 18. Mr. H told us that this helps with tonight's WebAssign. I'll use AX2E3 for an example. A represents the central atom of the molecule. X is attached to the A (a bonded pair) and E is the lone electron pairs. The numbers next to X and E are the number of X's and E's there are in the molecule. We ended with writing the Purpose of Lab CB1 and started to work on the data section individually.

Homework tonight is a WebAssign and to study for the pop quiz.