1. To Do 7 th 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

2. 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

3. Overall Goal: Properties For 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

4. 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

5. Ionic Bonding 5

6. 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)Na 2+ d)Na  e)Na 2  6

7. 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)O 2+ d)O  e)O 2  7

8. 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)O 2+ d)O  e)O 2  8

9. Elements/Ions Do Not “Want” To Lose Electrons! 9

10. Electron Affinity 10

11. 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)Na 2+ d)Na  e)Na 2  11

12. 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)O 2+ d)O  e)O 2  12

13. 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)O 2+ d)O  e)O 2  13

14. Elements/Ions Do Not “Want” To Lose Electrons! 14

15. 15

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17. A Covalent Bond 17