Across
- 2. a person who uses science knowledge to design something order to solve a problem
- 3. the solid part of Earth
- 4. vapor water in the form of a gas
- 6. different substances
- 7. reaction the process in which substances change
- 9. water that has been used and now contains harmful
- 11. a supply of something that is useful
- 12. the air that surrounds the Earth
- 13. all of the living things on Earth
Down
- 1. process of a gas turning into a liquid
- 5. process of a liquid turning into a gas
- 8. all of the liquid water and ice on Earth
- 10. a group of parts that work together