Across
- 5. harmful substance
- 6. device that spins to convert heat energy into kinetic energy
- 8. the process of burning fuel to produce heat and light
- 9. heat that comes from beneath the earth's surface
- 12. energy that comes from plants (like firewood)
- 14. material found in rocks that was used in nuclear fuel
- 15. result
- 17. original
- 18. materals that formed underground as plants and animals decay
- 20. a pollutant that increases the earth's ability to hold heat
Down
- 1. a fossil fuel that is a hard black substance
- 2. a liquid fossil fuel
- 3. a device to store chemical energy
- 4. a fossil fuel that occurs in the gas state
- 7. produces nuclear energy
- 10. energy from moving water
- 11. something made for a specific purpose
- 13. a material that releases energy as heat as it burns
- 16. the release of substances into the environment
- 19. device that changes kinetic energy to electrical energy