Across
- 3. calcium
- 4. phosphorus
- 6. period
- 10. energy levels
- 14. electronegativity
- 16. aluminum
- 17. family
- 22. lithium
- 24. neon
- 25. atomic radius
- 27. teacher
- 29. description
Down
- 1. valence
- 2. fluorine
- 5. oxygen
- 7. helium
- 8. ionization energy
- 9. carbon
- 11. nitrogen
- 12. sodium
- 13. beryllium
- 15. sulfur
- 18. chlorine
- 19. silicon
- 20. hydrogen
- 21. potassium
- 23. boron
- 26. argon
- 28. magnesium