Across
- 1. eletriccharge
- 3. families
- 4. Atomic number
- 7. atom
- 9. electron
- 10. base
- 11. groups
- 12. enzyme
- 15. acid
- 16. neutron
- 17. period
- 18. reduction
- 19. alcohol
Down
- 2. chemical formula
- 5. Chemical reaction
- 6. valence electron
- 8. energy levels
- 13. molecule
- 14. cation
- 17. proton