Across
- 3. element with atomic number 10
- 6. left of the staircase
- 8. right of staircase
- 10. number of families
- 13. atom with a positive charge
- 14. element with the symbol 'K'
- 15. row
Down
- 1. first element
- 2. creator of periodic table
- 4. outer shell
- 5. first family
- 7. element in the carbon family, fifth period
- 9. element that is good for your bones
- 11. family
- 12. atom with a negative