Across
- 2. Center of an atom
- 3. When one celestial body blocks another
- 4. Nuclear reaction powering the sun
- 10. Lightest and most abundant element
- 12. Water movement through a membrane
- 15. How plants convert sunlight to food
- 16. Pure substance on the periodic table
- 17. Gas we breathe to survive
- 19. Element essential to all life
- 20. Physics of very small particles
- 21. Negatively charged atomic particle
Down
- 1. Splitting an atomic nucleus
- 3. Protein that speeds up reactions
- 5. Positively charged atomic particle
- 6. Splits white light into colors
- 7. Fourth state of matter
- 8. Preserved remains of ancient life
- 9. Gas making up 78% of atmosphere
- 11. Complete set of DNA in an organism
- 13. Particle of light
- 14. Two or more atoms bonded together
- 18. Uncharged particle in an atom