Across
- 3. the solid part of Earth
- 5. all the living things on Earth
- 6. a supply of something that is useful
- 10. all the liquid water and ice on Earth
- 12. the air that surrounds Earth
- 13. when a gas turns into a liquid
- 14. a description of how something works or why something happens
Down
- 1. vapor water in the form of invisible gas
- 2. a group of atoms joined together
- 4. water that has been used and now contains harmful substances
- 7. matter that is made up of only one kind of atom or molecule
- 8. when a liquid turns into a gas
- 9. what you can observe or measure about something
- 11. the stuff that things are made of
- 13. reaction a process in which substances change into different substances