Thermal Energy Review

3. a balanced state in which a system is stable, such as when two or more samples are at the same temperature
6. when something stays mostly the same over time
7. The molecules of a system will transfer energy until the system reaches a stable state known as _______, in which all the molecules are moving at about the same speed.
9. Energy _______ created or destroyed.
11. When a thing gains or loses energy, the energy gained or lost is _______ among all the molecules of the thing.
12. a set of interacting parts forming a complex whole
15. when something becomes different over time
16. the energy that an object has because it is moving
18. the total kinetic energy of all the molecules that make up a sample
20. to move from one object to another or one place to another

1. When a thing gets hotter, its molecules are moving faster and have _______ kinetic energy.
2. When a thing gets colder, its molecules are moving _______.
3. At _______, the average kinetic energy (temperature) of the molecules in the system is the total kinetic energy (thermal energy) evenly divided by the number of molecules in the system.
4. a group of atoms joined together in a particular way
5. For things at the same temperature, the thing with more molecules has more total kinetic energy (thermal energy) than the thing with fewer molecules.
8. When a thing gets colder, its molecules are moving slower and have _______ kinetic energy.
10. Things are made of _______ (or other types of atom groups).
13. _______ is a measure of the average kinetic energy of the molecules of the thing.
14. a number that summarizes a set of data and that can be computed by adding all the numbers in a list and then dividing by the number of numbers in the list
15. the moment when two objects hit each other
17. to reach a conclusion using evidence and reasoning
19. When a thing gets hotter, its molecules are moving _______.
20. The _______ energy of a system does not change.