1. Heat and Phases
-Heat energy is related to the motion of the atoms and molecules – more heat energy means faster moving atoms and molecules and less heat energy means slower moving atoms and molecules

2. Heat and Phases
-Temperature is a measure of the average energy of molecular motion
-We measure temperature using a thermometer.
-Heat is energy transferred from a higher temperature to one at lower temperature.

3. Heat and Phases Phases Solid – molecules are barely moving
0°C or 32°F = freezing point of water
Liquid – molecules are moving
Gas – molecules are moving rapidly
100°C or 212°F = boiling point of water

4. Heat and Phases
Phases
-When a substance changes from one phase to another, the amount of energy is changing. Heat is either released or absorbed.
-Melting and evaporation require energy to overcome the bonds of attraction
-Freezing and condensation release heat into environment; bonds are formed

5. Heat and Phases
Changes in Phases

6. Phases Cartoon Directions:
Now that you know how heat energy affects phases, draw three single panel cartoons that show how solids are different from liquids, and how those two are different from gases.