Science crossword puzzle

1234567891011121314151617181920
Across
  1. 1. measure of how much space a sample of matter takes up is?
  2. 5. mass is often measured I what?
  3. 8. what comes from petroleum?
  4. 9. the number of what in an atom determines what element it is?
  5. 10. what is a quantity that scientists use to measure force?
  6. 11. an object's ability to float is called...
  7. 14. each what has it's own density?
  8. 16. how many elements are there?
  9. 17. on a magnet opposite poles do what?
  10. 20. compounds can only be broken up by what?
Down
  1. 2. an objects weight depends on it's what in the universe.
  2. 3. a measure of the amount of matter in an object is...
  3. 4. petroleum is a complex mixture of what?
  4. 6. metals like copper are good at what?
  5. 7. something that has mass and takes up space.
  6. 12. what are the basic building blocks of matter?
  7. 13. what has north and south poles?
  8. 15. three-fourths of an elements are what?
  9. 18. what measures mass?
  10. 19. a measure how tightly packed a sample of matter is called what?