1. Chapter 6 Section 2- changes of state

2. Kinetic and Potential Energy  Kinetic energy- the energy of motion  faster the particles move then the greater the KE  Gases have the greatest KE, particles are moving the fastest in this state of matter  Temperature- the average KE of all the particles in the object  Potential energy- stored energy  PE increases when objects are farther apart and decreases when objects get closer  Chemical PE is due to the positions particles relative to other particles  Gases have the most PE

3. Thermal energy  The total potential and kinetic energies of an object  Can change a state of matter by increasing or decreasing the thermal energy of the object

4. Solid to liquid or liquid to solid  Melting- S to L- thermal energy added  Thermal energy and temperature increase until the melting point.  At this point the temperature does not change but the PE is increasing (particles are moving farther apart)  Freezing is the reverse of  melting

5. Liquid to Gas or Gas to Liquid  Liquid to gas- vaporization  Vaporization within a liquid is called boiling  KE of the particles increases until it reaches the boiling point  Then temperature remains the same but the potential energy changes  Evaporation- occurs on the surface of a liquid  Condensation- the reverse process- if a gas loses enough thermal energy it will become a liquid

7. Solid to gas or gas to solid  Sometimes the intermediate state is not necessary  Dry ice- solid carbon dioxide changes to a gas with no liquid state  This is called sublimation  Deposition- going from gas to solid with no liquid state  Frost on the grass

8. Conservation of mass and Energy  Two famous laws  Matter can neither be created nor destroyed  Matter can change form or state but you are not losing anything or gaining anything