Unit 3 Vocabulary

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Across
  1. 2. the number of protons in the nucleus of an atom
  2. 3. vertical columns on periodic table
  3. 5. matter that is composed of only one type of atom
  4. 7. isotopes have different numbers of...
  5. 8. protons + neutrons
Down
  1. 1. horizontal rows on periodic table
  2. 4. subatomic particle with a postive charge
  3. 6. elements located on the left of the periodic table