Across
- 2. Heat energy from within the Earth
- 7. Organic matter used as a renewable energy source
- 8. The wearing away of land by water, wind, or ice
- 10. A black rock used as a fossil fuel
- 13. Harmful substances in the environment
- 14. Naturally occurring solid substances found in the Earth
- 16. A liquid fossil fuel used for energy and products
- 17. The protection and wise use of natural resources
- 19. A resource that can be replaced naturally
- 20. Process of making new items from used materials
Down
- 1. Clearing or cutting down of forests
- 3. Air in motion that can be used to generate energy
- 4. A gaseous fossil fuel used in heating and cooking
- 5. A substance burned to produce energy
- 6. A resource that cannot be replaced quickly
- 9. Remains of ancient organisms preserved in rock
- 11. Energy generated from moving water
- 12. Decayed organic material used as fertilizer
- 15. Using resources in a way that meets current and future needs
- 18. Energy from the sun