Across
- 4. Used to describe chemical reactions
- 5. Reducing the amount of energy used
- 6. A change that makes a new substance that cannot be reversed
- 9. Energy sources that will eventually run out
- 12. Energy sources from the decompositions of organisms millions of years ago
Down
- 1. Renewable energy source that uses the sun to generate electricity
- 2. Renewable energy source that uses wind power to generate electricity
- 3. Substance that exists before a chemical reaction begins
- 7. Renewable energy from the heat in the interior of the earth
- 8. Matter that can be observed by changing the substance
- 10. Substance that forms as a result of a chemical equation
- 11. Renewable energy source that can be burned and used as a source of fuel