Across
- 2. shortcut
- 8. valence dots
- 12. outer
- 13. orbitals
- 16. opposite
- 17. positive
- 18. arrows
- 20. unknown
Down
- 1. duality
- 3. subdivision
- 4. energy level
- 5. lowest energy
- 6. charge
- 7. build
- 9. higher energy
- 10. arrangement
- 11. light partcicle
- 14. negative
- 15. color lines
- 19. unpaired