Across
- 4. Earth's main resources of renewable energy
- 6. water that is held below the ground
- 9. from timy bits of weathered rock, animal remains, or plants that pile up in layers
- 10. a mixture of minerals, rocks and other things
- 12. color, streak, and luster
- 14. types of materials are in it
- 15. a material that is burned for its energy
- 16. how light reflects off of it
- 17. bits of decaying plants and animals in soil
Down
- 1. types of fossils
- 2. resource a material on Earth that is necessary or useful to people
- 3. changed by heating and squeezing
- 5. a solid, nonliving substance found in nature
- 7. plants, water, air
- 8. nonliving material made of one or more minerals
- 11. topsoil, subsoil, bedrock
- 13. coal, natural gas, and oil