1. Creating a Positive Learning Environment for Everyone
Be respectful of your classmates
Save conversation for clicker portions of lecture
Put cell phones in “airplane” mode
Turn off tablets
Close laptops

2. Announcements Pre-lab due this week at the start of lab!
Electronic HW #6 Type 1 due Monday, Nov. 27th at 7:00pm
Electronic HW #6 Type 2 due Wednesday, Nov. 29th at 7:00pm

3. Exothermic: more energy leaves the system overall
Endothermic: more energy goes into the system overall
2H2 + O2  2H2O
2H2O  2H2 + O2

4. Clicker #1
If the reactants are defined as the system, is this an endothermic or exothermic process?
A) endothermic
B) exothermic

5. Clicker #2
How would the energy diagram for this reaction look?

6. Example #1
Is the freezing of water an endothermic or exothermic process? (The system is underlined.)
Exothermic

7. Clicker #3
Is the boiling of water an endothermic or exothermic process? (The system is underlined.)
A) endothermic
B) exothermic

8. Example #2
Is an activated cold pack an endothermic or exothermic process? (The system is underlined.)
Endothermic

9. Clicker #4
Is an activated hot pack an endothermic or exothermic process? (The system is underlined.)
A) endothermic
B) exothermic

10. Clicker #5
Is a racquetball frozen by liquid nitrogen an endothermic or exothermic process? (The system is underlined.)
A) endothermic
B) exothermic

11. Example #3
Is the thermite reaction (the chemical reaction) an endothermic or exothermic process? (The system is underlined.)
Exothermic

12. Overall goal: Atomic Structure Chemical Bonding 3D Molecular Structure
Molecular Properties

13. Various Atomic Models
Dalton: Law of Definite Proportions. (He concludes that atoms are indivisible and have mass.)
J.J. Thompson: atoms emit tiny negative particles. (Therefore atoms not indivisible!)
William Thompson: formulates the Plum Pudding Model. (Electrons moving in a positively charged cloud.)
Rutherford: Some α-particles bounce back when shot at atoms.

14. Clicker #6
If alpha particles (which are the positively charged nuclei of helium atoms) bounce back when shot at atoms, what is most likely causing them to bounce away?
Negatively charged particles
Positively charged particles
Positively OR negatively charged particles
Neutral particles
No particles
(There is a concentration of mass with a positive charge in the atom.)

15. Reading Homework for Thursday
Review the various atomic models in your textbook (Sections 4.3, 4.5)
Read about electromagnetic radiation (Sections )