Across
- 2. Earth's closest star
- 3. Body's control center
- 6. Source of Earth's heat
- 7. Unit of measurement for energy
- 9. Natural disaster caused by tectonic plates
- 14. Process of evolution
- 16. Electrically charged particle
- 17. Compound essential for life
- 19. Study of living organisms
- 20. Process of converting sunlight into energy
Down
- 1. Largest planet in the solar system
- 4. Particle smaller than an atom
- 5. Earth's natural satellite
- 8. Protective layer in the atmosphere
- 10. Study of celestial bodies
- 11. Outer layer of the Earth
- 12. Study of the Earth's atmosphere
- 13. Building blocks of matter
- 15. Force that attracts objects
- 18. Chemical symbol for gold