Across
- 3. A material found in nature that is useful to humans.
- 6. Harmful waste caused by people.
- 9. A solid fossil fuel that can be burned for energy.
- 10. Heat that comes from the earth.
- 11. A source of energy formed from dead plants and animals.
- 12. To change something from one form to a different form.
- 13. A type of energy that comes from resources that could run out or that take a long time to be replaced.
Down
- 1. The accessibility of materials found in nature for people.
- 2. All living things and organic matter.
- 4. electrical power that is generated from moving water.
- 5. A liquid fossil fuel that can be burned for energy.
- 7. The energy that holds matter together.
- 8. A source of energy that can be restored more quickly than it is used.