Periodic Puzzle

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Across
  1. 1. from the Greek 'light-bearer' burns bright white
  2. 5. raises the pitch of your voice
  3. 7. known to smell 'like rotten eggs'
  4. 8. these footprints contribute to global warming
  5. 9. as a South Campus major, I just find math...
  6. 13. mixed with hydrogen, it produces ammonia
  7. 14. atomic number 18
  8. 16. found in dairy
  9. 17. used in many lubricants
  10. 19. populary known as a cleaning product
  11. 20. popular seasoning
Down
  1. 2. fish get it through their gills
  2. 3. find this in a roll in your pantry
  3. 4. variant of the pink crystal fluorite
  4. 6. popular dietary supplement
  5. 10. two of these atoms are in water
  6. 11. second in group 2
  7. 12. with an atomic mass of 39, this supports bone density
  8. 15. mood-stabilizing medication
  9. 18. burned out signs at gas stations are often