Across
- 5. Basic unit of life
- 6. Smallest unit of matter
- 7. Process plants use to make food
- 11. Force pulling objects toward Earth
- 13. Scientist who discovered gravity
- 14. Element found in all living things
Down
- 1. Gas used in balloons
- 2. Green pigment in plants
- 3. Positively charged particle
- 4. Liquid turning into gas
- 8. Gas needed for breathing
- 9. Needed to do work
- 10. Force that resists motion
- 12. Smaller than bacteria
- 13. Cell that carries messages in the body