Periodic Table Crossword Puzzle

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Across
  1. 6. diamonds are made from it
  2. 10. named after Ernest Rutherford
  3. 11. used in balloons
  4. 12. used in jewelry
  5. 13. named after Dmitri Mendeleev
  6. 15. lightest element on the periodic table
  7. 17. used in magnets
  8. 18. named after Marie Curie
  9. 20. used to make electronics
Down
  1. 1. used in fluorescent lights
  2. 2. most radioactive element
  3. 3. contained in dairy products
  4. 4. used in nuclear power plants
  5. 5. has 4 protons
  6. 7. breathed by humans
  7. 8. contrary to popular belief, not used in pencils
  8. 9. used in thermometers
  9. 14. lightest solid element
  10. 16. most common element in the atmosphere
  11. 19. named after Albert Einstein