Thermal Energy

4. transfer of energy from warmer substances to cooler substances
7. anything that takes up space and can be weighed
8. particles that are too small to see with the unaided eye
10. a material that has lots of air pockets like styrofoam
13. the variable to observe for effect caused by the change
14. the set of parts that work together to complete a goal or task
16. a system in which no matter can get in or out
17. a system in which matter can get in or get out of
20. the process which water in its gaseous form is turned into liquid water
23. happens when heat is transferred through the air from something that is hot to something cold

1. measure of the average kinetic energy of particles in a substance
2. a factor you want to change or control in an investigation
3. variables that are kept the same
5. when heat in liquids and gases moves around
6. heat energy; motion of particles in a substance
9. phase of matter that has particles that are close together but move freely
11. when thermal energy is transfered through particle collisions between a hot object touching a cold object
12. the variable to change because you want to test it
15. phase of matter that has particles that are close together and do no move freely but vibrate in place
18. process where water slowly changes from a liquid to a gas
19. the edge of the system
21. the average of a set of numbers
22. the energy of movement