Periodic Crossword

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Across
  1. 1. has a atomic number of 1
  2. 4. what is used in guns
  3. 5. most reactive metal
  4. 8. is in group 9 period 4
  5. 10. has the biggest atomic number
  6. 11. it is in a balloon
Down
  1. 2. It is mostly what our air is made out of
  2. 3. it is in public pool
  3. 5. most reactive non metal
  4. 6. It is a planet
  5. 7. it makes your bones stronger
  6. 9. what you get when you 2nd