Thermal Energy

4. When light bounces off an object.
7. When light passes through an object.
10. A state of matter that has no definite shape and no definite volume.
11. A state of matter that has definite shape and definite volume.
14. The change of state from a liquid to a solid.
15. The change of state from liquid to gas.
17. As the average kinetic energy of particles increase, the temperature will ______.
18. A material that reduces the transfer of heat energy.
19. A system where nothing can get in or out.
20. A system where anything can get in or out.

1. The change of state from gas to liquid.
2. A smallest part of a substance.
3. The energy of motion
5. When two particles collide and transfer energy.
6. When an object is hot, the particles move _______.
8. The measure of the average energy of motion of particles in a substance; how hot .
9. A state of matter that has no definite shape but has definite volume.
12. The transfer of heat energy from one object to another by direct contact.
13. The change of state from a solid to a liquid.
16. Anything that has mass and takes up space.