Dr. Gray's Awesome Crossword Puzzle

1234567891011121314151617181920
Across
  1. 4. Two of this + 1 oxygen makes water
  2. 5. The degree of compactness of a sustance
  3. 6. Not really Pb, but its in your pencils
  4. 8. Highly compressed carbon
  5. 11. A Hollywood theater, atomic number 46
  6. 14. Any of two or more forms of an element, having the same number of protons in the nucleus, with a different number of neutrons in the nucleus.
  7. 15. This force resists motion, resulting in heat
  8. 17. Force that attracts a body to another body with mass
  9. 20. A 4th state of matter not solid, liquid or gas, present in stars and fusion reactors
Down
  1. 1. A process in which the nuclei of atoms are joined
  2. 2. energy in motion
  3. 3. sugar, gasoline, methane
  4. 7. A particle of matter with the same mass as an electron but an opposite charge
  5. 9. Closest planet to the Sun, element symbol Hg
  6. 10. My atoimic number is 13
  7. 12. The medieval forerunner of chemistry, based on the supposed transformation of matter.
  8. 13. The spliting of an atom
  9. 16. A system of millions or billions of stars, the Milky Way
  10. 18. The world's first polymath, first multi-genius
  11. 19. A non-crytalline amorphous solid