Across
- 3. alkali metal
- 6. 12 neutrons
- 7. Goes in balloons
- 10. atomic mass 63.546
- 12. Goes in pools
- 13. Atomic mass 15.999
Down
- 1. 19 protons
- 2. Atomic number 28
- 4. Alkaline earth metal
- 5. group 14 period 6
- 7. 1 electron
- 8. Transition metal
- 9. atomic mass 107.87
- 11. Atomic number 30