Periodic table

1234567891011121314151617181920
Across
  1. 3. Least reactive element
  2. 7. Charge of +1
  3. 8. Name given to elements with the same number of protons but different number of neutrons
  4. 9. Element has an electronic configuration of 2, 8, 8, 1
  5. 10. Element is found in period VI and has 2 valence electrons
  6. 11. Charge of 0
  7. 13. Element is found in balloons
  8. 14. Horizontal column in the periodic table
  9. 16. Element has an electronic configuration of 2, 8, 8, 8, 8, 2
  10. 18. Element has an electronic configuration of 2,8 3
  11. 19. Elements found in group VII, period IV
  12. 20. Element is the least reactive in group VII
Down
  1. 1. Mass of 0
  2. 2. Element is used in plastic surgery
  3. 3. Vertical column in the periodic table
  4. 4. Element is the least reactive in group I
  5. 5. Most reactive non-metal
  6. 6. Element is a yellow/green gas
  7. 9. Element is found in period III and has 5 valence electrons
  8. 12. Number of electrons found in the first electron shell
  9. 15. Most reactive element in the periodic table
  10. 17. Another name for group VII