Tic tac toe crossword

12345678910111213
Across
  1. 1. state of matter that takes the shape of its container
  2. 5. subatomic particle with no charge
  3. 8. number of protons in an element
  4. 10. the amount of matter in an object
  5. 12. subatomic particle with a positive charge
  6. 13. the amount of mass per volume
Down
  1. 2. molecule that has gained or lost electrons
  2. 3. state of matter similar to gas
  3. 4. smallest form of a chemical element
  4. 5. the center of an atom, made of protons and neutrons
  5. 6. state of matter with no definite shape or volume
  6. 7. mixture made up of multiple substances
  7. 9. subatomic particle with a negative charge
  8. 11. state of matter with a definite shape and volume