1. Phase Changes
What did one water molecule say to another water molecule about vapor?
Don’t worry it’s just a phase he’ll cool down.

2. Characteristics of Phase Changes
_________________are also referred to as phases.
Phase Change: ____________________________________________________________________________________________________________________________________

3. Description of Phase Change
PHASE CHANGES
Description of Phase Change
Term for Phase Change
Heat Movement During
Phase Change
__________________
Melting
Heat _________________the solid as it melts.
Freezing
Heat _________ the liquid as it freezes.

4. Description of Phase Change
PHASE CHANGES
Description of Phase Change
Term for Phase Change
Heat Movement During
Phase Change
__________________________
Vaporization, which includes boiling and evaporation
Heat _____________ the liquid as it vaporizes.
Condensation
Heat ___________ the gas as it condenses.

5. Phase Change graphic ______________ ______________ ___________

6. Average Kinetic Energy = Temperature
Temperature ______________________ ____________________________________________________. Meaning that temperature measures movement of particles.
Temperature is ______________________ _____________________ kinetic energy of the molecules of a substance. That means if you double the Kelvin temperature of a substance, you double the average kinetic energy of its molecules.
When the average kinetic energy of the molecules goes up (a rise in temperature), ____________________________________________________________________. A change in average kinetic energy is not directly proportional to a change in average speed.

7. Using Temperature to Indicate Phase Change
________________________________________________________________________________
___________________________________________________________.

8. Water Phase Change GraphD
100
gas C
Temperature º C.
liquid B
Pass out the Water Phase Change Graph blank to all students.
As we work through the phase changes, please add to your graph.
This is a graph that shows the energy and temperature changes as water turns from a solid, ice, to a liquid, water, and finally to a gas, water vapor. As we make additions on the board, you will make the additions to your paper.
Mark the letters A, B, C, D and E.
(click) First, we show that the molecules of water in the solid form are tightly packed and in a regular pattern forming crystals. We’ll take a closer look at the actual pattern later. Draw the crystal lattice here showing that water is a solid below zero degrees Celcius.
(click) Next we show water molecules in the liquid state here between zero and 100 degrees Celcius. Draw the molecules a bit farther apart and without a crystal structure.
(click) And here we have water in the gas state with the molecules farther apart A
solid
Heat (thermal energy)

9. Water Phase Change GraphD
100
gas C
Temperature º C.
liquid B
As water changes from solid to liquid to gas, what is happening to the energy of the molecules?
(increasing) (click)
What is happening to the temperature?
(increasing) A
solid
Heat (thermal energy)

10. Water Phase Change GraphD
_________
100
_______ C
Temperature º C. B
________
When the ice reaches zero degrees what starts happening?
(melting from solid ice to liquid water) (click)
If we were moving in the opposite direction, with decreasing energy and temperature, from liquid water to solid ice, what would that be called?
(Freezing) (click)
As the liquid water reaches 100 degrees, what happens?
(change from liquid to gas, boiling) (click)
If we were moving in the opposite direction, with decreasing energy and temperature, from water vapor to liquid water, what would that be called?
(condensation, condensing) (click)
Answer the questions of the bottom of your paper.
__________ A
Heat (thermal energy)

11. F D E B C A

12. -Heat change in _____________ -Particles move ______________
Between A and B
-Heat change in _____________
-Particles move ______________
-Temp._____________________
-Solid
Between D and E
-Heat change in _________________
-Particles get ___________________
-Temp. ________________________
-Boiling
Between B and C
-Heat change in Potential Energy
-Particles ___________________
-Temp. _____________________
-MELTING
Between E and F
-Heat change in _________________
-Particles ______________________
-Temp. ________________________
-Gas
Between C and D
-Heat change in ______________
-Particles ___________________
-Temp. ___________________
-liquid