Across
- 6. groups 3-12
- 8. Staircase
- 11. First Metaloid
- 12. right of staircase
- 15. Positively charged electron
- 17. 109 protons
- 18. The most special element
Down
- 1. 1st period
- 2. left of staircase
- 3. a subatomic particle of about the same mass as a proton but without an electric charge
- 4. Number of protons
- 5. Protons and neutrons
- 7. charged electron
- 9. gives element its atomic mass
- 10. Row 3 group 2
- 13. How many electrons does energy level 2 hold
- 14. bonds attraction between oppositely charged ions
- 16. Negatively charged electron