Across
- 2. Organic matter that can be a source of energy; the total mass of the organisms in a given area
- 3. A liquid mixture of complex hydrocarbon compounds;used widely as a fuel source
- 4. A mixture of gasoline and alcohol that is used as a fuel
- 7. Energy received by the Earth from the Sun in the form of radiation
- 8. Rain, sleet, or snow that contain a high concentration of acids
- 9. A non-renewable resource formed from the remains of organisms that lived long ago
- 11. The process of recovering valuable or useful materials from waste or scrap
- 12. Photochemical haze that forms when sunlight acts on industrial pollutants and burning fuels
- 13. Energy produced by heat within the Earth
- 14. Energy released by a fission or fusion reaction, the binding energy of the atomic nucleus
Down
- 1. Any natural material used by humans, such as water, petroleum, minerals, forests and animals
- 5. Electrical energy produced by water
- 6. The energy released when a chemical compound reacts to produce new compounds
- 10. The use of a windmill to drive an electric generator
- 15. A fossil fuel that forms underground from partially decomposed plant material