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 States of matter are also referred to as phases. Phase Change: the reversible physical change that occurs when a substance changes from one state of matter to another

3. PHASE CHANGES Description of Phase Change Term for Phase Change Heat Movement During Phase Change Solid to liquid Melting Heat goes into the solid as it melts. Liquid to solid Freezing Heat leaves the liquid as it freezes.

4. Description of Phase Change Term for Phase Change Heat Movement During Phase Change Liquid to gas Vaporization, which includes boiling and evaporation Heat goes into the liquid as it vaporizes. Gas to liquidCondensation Heat leaves the gas as it condenses. PHASE CHANGES

5. Phase Change graphic Melting Freezing Vaporization Condensation

6. Average Kinetic Energy = Temperature Temperature is a measurement of the average kinetic energy of the particles within a substance. Meaning that temperature measures movement of particles. Temperature is proportional to the average 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), the average speed of the molecules increases. A change in average kinetic energy is not directly proportional to a change in average speed.

7. Using Temperature to Indicate Phase Change Whenever there is a plateau there is a phase change. This means that there is two phases of the substance at the same time.

8. Heat (thermal energy) Temperature º C. 100 0 A B C D E solid liquid gas Water Phase Change Graph

9. Heat (thermal energy) Temperature º C. 100 0 A B C D E solid liquid gas Water Phase Change Graph

10. Heat (thermal energy) Temperature º C. 100 0 A B C D E melting freezing condensing boiling Water Phase Change Graph

11. B C A F ED