Matter

12345678
Across
  1. 3. Negatively charged particle outside nucleus
  2. 4. Anything that has volume and mass
  3. 5. Center of an atom. Contains protons and neutrons
  4. 7. Same number of protons, but different neutrons
  5. 8. Can't be broken down into simpler substances
Down
  1. 1. Atom that has gained or lost an electron
  2. 2. Number of protons in an atom
  3. 4. Number of protons and neutrons in an atom
  4. 5. Found in nucleus. Has no charge
  5. 6. Found in nucleus. Has a positive charge