Chemistry final crossword

12345678910111213141516171819202122232425
Across
  1. 3. cause the gas cloud to contract until fusion
  2. 4. have a thermal spectrum
  3. 7. Original temperature of the universe is 3000
  4. 8. The universe used to be
  5. 10. website that solves equations
  6. 15. the third most common element in the cosmos
  7. 17. the CMB has very long
  8. 19. individually separate and distinct
  9. 20. All atoms with more than 82 protons are this
  10. 21. Lighter elements sometimes have too many
  11. 23. The matter in the universe is about 25%
  12. 25. Protons and neutrons have nearly the same
Down
  1. 1. A neutron could turn into one
  2. 2. The matter in the universe is about 75%
  3. 5. Atoms of the same element but different mass
  4. 6. The nuclei of some atoms are
  5. 9. does not leave behind a white dwarf
  6. 11. radioactive elements often emit them
  7. 12. from space the sun looks
  8. 13. The Big Bang was not a
  9. 14. Electrons are much less
  10. 16. the energy released by
  11. 18. a more massive star has more
  12. 22. push against each other and prevent collapse
  13. 24. space is pretty much