To Do

7th HW assignment due Friday, April 10th by 10 pm.

Quiz #5 on Friday, April 10 in Discussion.

Continue reading Chapter 8 and doing the suggested homework.

1

Exam #2 High score: 75/80

Lon-Capa percentages are decreasing.

#18: homework question (chapter 7, #116).

The sum of the points so far is about 40% of the total possible points for the semester.

2

Overall Goal: PropertiesFor example, why is water a liquid but methane a gas?

To understand properties, we need to know molecular structure, which means we need to understand bonding, which is why we studied atomic structure.

3

Chemical Bond

Force that holds groups of two or more atoms together and makes them function as a unit.

Atoms will bond if the molecule is more stable than the two separated atoms (lower energy state).

4

Ionic Bonding

5

Clicker Question

Consider different “sodium particles” (atom or ions) in separate evacuated containers. Which of the following sodium species is lowest in energy?

a) Na b) Na+ c) Na2+ d) Na e) Na2

6

Clicker Question

Consider different “oxygen particles” (atom or ions) in separate evacuated containers. Which of the following oxygen species is lowest in energy?

a) O b) O+ c) O2+ d) O e) O2

7

Clicker Question

Consider different “oxygen particles” (atom or ions) in separate evacuated containers. Which of the following oxygen species is second lowest in energy?

a) O b) O+ c) O2+ d) O e) O2

8

Elements/Ions Do Not “Want” To Lose Electrons!

9

Electron Affinity

10

Clicker Question

Consider different “sodium particles” (atom or ions) in separate evacuated containers. Which of the following sodium species is lowest in energy?

a) Na b) Na+ c) Na2+ d) Na e) Na2

11

Clicker Question

Consider different “oxygen particles” (atom or ions) in separate evacuated containers. Which of the following oxygen species is lowest in energy?

a) O b) O+ c) O2+ d) O e) O2

12

Clicker Question

Consider different “oxygen particles” (atom or ions) in separate evacuated containers. Which of the following oxygen species is second lowest in energy?

a) O b) O+ c) O2+ d) O e) O2

13

Elements/Ions Do Not “Want” To Lose Electrons!

14

15

16

A Covalent Bond

17