Across
- 5. a fossil energy source that formed deep beneath the earth's surface.
- 8. the energy that earth receives from the sun
- 9. energy comes from sources that will run out or will not be replenished for thousands or even millions of years.
- 10. a source of water power in the sea
- 11. energy from a source that is not depleted when used, such as wind or solar power.
- 12. a machine for producing electricity
Down
- 1. a fuel formed by natural, geological processes.
- 2. renewable organic material that comes from plants and animals.
- 3. carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
- 4. Uranium and plutonium are ____ fuels
- 6. relating to or produced by the internal heat of the earth.
- 7. energy that harnesses the power of water in motion—such as water flowing over a waterfall—to generate electricity.