Across
- 2. Nuclear reaction powering the sun
- 4. Noble gas that makes balloons float
- 5. Preserved remains of ancient life
- 7. Two or more atoms bonded together
- 12. Protein that speeds up reactions
- 15. Force that keeps us on Earth
- 16. Negatively charged atomic particle
- 18. Lightest and most abundant element
- 21. Fourth state of matter
- 22. Pure substance on the periodic table
- 23. Positively charged atomic particle
- 24. Splitting an atomic nucleus
- 25. Electric potential difference
Down
- 1. Cell division process
- 3. Complete set of DNA in an organism
- 6. Gas we breathe to survive
- 8. When one celestial body blocks another
- 9. Range of light wavelengths
- 10. Gas making up 78% of atmosphere
- 11. Object that attracts iron
- 13. Injection that prevents disease
- 14. Splits white light into colors
- 17. Uncharged particle in an atom
- 19. Center of an atom
- 20. Element essential to all life
- 23. Particle of light