Thermal Energy

3. ENERGY Energy from the Sun that can be used to generate heat or electricity.
4. Heat transfer in fluids caused by lower-density particles rising and higher-density particles sinking.
6. POINT The temperature at which a solid changes into a liquid.
8. The type of electromagnetic wave responsible for heat transfer by radiation.
13. COOLING Cooling that happens because high-energy particles leave, reducing the energy of the remaining particles.
15. HEAT Energy added or removed during a change of state without a temperature change.
16. A measure of the average kinetic energy of particles.
17. The change of state from a liquid to a gas that occurs throughout the liquid.
18. Heat transfer by infrared waves that does not require a medium.

1. The escape of higher-energy particles from the surface of a liquid.
2. A process that decreases the internal energy of a substance.
5. EQUILIBRIUM The condition reached when energy transfer stops because particles in two objects have the same average kinetic energy.
7. A surface or colour that takes in thermal radiation easily.
8. ENERGY The total random kinetic and potential energy of particles in a substance.
9. MODEL Amodel used to explain the motion, forces, and spacing of particles in solids, liquids, and gases.
10. ENERGY Energy that is transferred from a hotter object to a cooler object.
11. Heat transfer through a solid by particle vibrations and moving electrons.
12. The change of state from a solid to a liquid.
14. A process that increases the internal energy of a substance.
17. POINT The temperature at which a liquid changes into a gas.