Periodic table!

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Across
  1. 3. the protons that are = to the electrons
  2. 7. anything that has mass and takes up space
  3. 9. the part of the atom that has no charge
  4. 10. the name of the element
  5. 12. the number of protons + neutrons (P+N)
Down
  1. 1. the smallest whole unit of matter
  2. 2. the center of an atom
  3. 4. the letter(s) that represent an element
  4. 5. the negatively charged part of an atom
  5. 6. a thing made of one type of atom that can't be broken
  6. 8. positively charged part of an atom
  7. 11. how much matter an object is made up of