Across
- 5. Energy in the form of electromagnetic radiation emitted from the Sun
- 6. Fuel consisting of the remains of organisms preserved in rocks in the earth's crust
- 7. An industrial plant for purifying a crude substance
- 10. A fossil fuel in the gaseous state
- 12. A large natural or artificial lake used as a source of water supply
- 13. A flammable liquid ranging in color from clear to very dark brown and black
- 14. A natural resource that is replenishable by natural processes
- 16. Materials on Earth available for human use
Down
- 1. Energy made by the force of water
- 2. A rock formed from prehistoric plant remains
- 3. Any compound obtained from petroleum or natural gas
- 4. A radioactive metal used as a fuel in nuclear reactors
- 8. A resource that is not able to be renewed
- 9. Energy derived from the heat in the interior of the earth
- 11. A dark oil consisting mainly of hydrocarbons
- 15. Energy of the wind