Across
- 3. radiant energy emitted by the sun.
- 5. hydroelectric power.
- 7. a form of solar energy.
- 9. energy he energy released during nuclear fission or fusion,
- 11. energy-is a resource of economic value that cannot be readily replaced by natural means at a quick enough pace to keep up with consumption.
- 12. a combustible black or dark brown rock consisting mainly of carbonized plant matter,
- 13. gas-flammable gas, consisting largely of methane and other hydrocarbons
- 14. the total mass of organisms in a given area or volume.
Down
- 1. the action of preserving something.
- 2. fuels
- 4. relating to or produced by the internal heat of the earth.
- 5. is a zero-emission fuel burned with oxygen.
- 6. a viscous liquid derived from petroleum,
- 8. prevention of wasteful use of a resource.
- 10. Energy-energy from a source that is not depleted when used, such as wind or solar power