Across
- 2. Period 1, Group 18
- 4. Symbol "H"
- 5. Period 3, Group 16
- 7. Found between elements with a mass of 14 and 19
- 9. Period 4, Group 1
- 11. 2 energy levels, 2 valence electrons
- 14. Period 2, Group 18
- 17. Period 3, Group 2
- 18. Period 4, Group 2
- 19. Atomic number is 15
Down
- 1. The first gas at room temperature in period 2
- 3. 3 energy levels, Group 17
- 6. Non metal in period 2, is missing 1 electron
- 8. 6 protons, 6 Neutrons
- 10. Mass number 27
- 11. Period 2, Group 13
- 12. Period 2, Group 1
- 13. A noble gas in period 3
- 15. Has 14 protons and 14 neutrons
- 16. Mass number 23