Across
- 4. power that is generated from moving water
- 7. cannot be replaced quick enough
- 9. a dark brown rock
- 10. the flow of electrical power
- 11. a colorless liquid
- 12. energy from a source that is not depleted when used
- 13. plant-based material used as a fuel for heat
- 15. a viscous liquid
- 16. power produced by the surge of ocean waters
Down
- 1. colorless,odorless substance of the chemical elements
- 2. mixture of gases which are rich in hydrocarbons
- 3. made from decomposing plants and animals
- 5. a natural movement of air
- 6. heat energy from the earth
- 8. energy stored inside a atom
- 14. light and heat that comes from the sun