Across
- 3. gases that surround the Earth or another planet
- 4. room with scientific equipment
- 5. positive electrical charge
- 7. the state of the atmosphere at a certain place and time
- 9. made of two or more different elements
- 10. a material's mass per unit volume
- 14. found on periodic table
- 18. smallest unit of an organism
- 19. always has volume and mass
- 20. the force that attracts a body to the center of the Earth
Down
- 1. the amount of matter that makes up an object
- 2. a negative charge, found in all atoms
- 5. made of one particle or substance
- 6. the basic material for matter
- 8. biological community of interacting organisms
- 11. the ability to do work
- 12. the amount of space that something occupies
- 13. no electrical charge
- 15. the average weather in an area over a period of time
- 16. a form of energy that comes from charged particles
- 17. the action or process of moving or being moved