1. Think First
Retake tests after school TODAY!
In your composition book explain the movement and position of molecules as a substance is moving from a solid to a liquid and then from a liquid to a gas.

2. Learning Target: I can explain phase changes in terms of energy transfer and interpret a phase diagram.
Frayer Model
Create a Frayer Model for each of the following six terms about phase changes. Melting, Vaporization, Sublimation, Condensation, Deposition, Freezing.
This is worth 10 test points…two test points for each term (Yes, that equals 12. So be thankful for the possibility of earning two extra credit test points.)
See the Frayer Model example on the board. You may use the back or your paper.
When you are done, staple your Frayer Models together and keep them with you. We will review them as a class before the end of the period. At the end of the period you will turn them into the basket.
Finish by ________.
If you finish early, study the phase diagrams on page 409.

3. Phase Changes
When energy is added or removed from a system, one phase can change into another. E = energy required, -E = energy released
Melting (E)
Vaporization (E)
Sublimation (E)
Condensation (-E)
Deposition (-E)
Freezing (-E)

4. Melting Lets think about ICE
Energy absorbed by ice is used to disrupt the hydrogen bonds holding the water molecules together.
Amount of energy required to melt one mole of solid depend on the strength of the forces holding the molecules together.

5. Vaporization
Particles that escape from the liquid enters the gas phase. When vaporization occurs only at the surface of a liquid, the process is called evaporation
We control our body temperature by evaporation.

6. Sublimation
The process which a solid changes directly to a gas without first becoming a liquid.
i.e Freeze drying

7. Condensation Process by which a gas or a vapor becomes a liquid.
Formation of hydrogen bonds  energy is released.
Causes?
Contact with cold surface  from droplets or dew
Layer of new air near the ground cools  produces fog.

8. Deposition and Freezing
Substance changes from a gas/vapor to a solid without becoming a liquid.
Energy is released
Example: FROST, SNOWFLAKES
Freezing
Heat is removed, molecules loose kinetic energy.
Hydrogen bonds keep molecules fixed/frozen.
Converting into a crystalline solid.

9. Phase Diagrams
Graph of pressure versus temperature that shows in which phase a substance exists under different conditions of temperature and pressure.

10. Phase diagram for water

11. CO2 Phase Diagram