Chemistry Puzzle

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Across
  1. 1. the amounts of ring in an electron cloud
  2. 4. a negative charge in an atom
  3. 6. the center of an atom
  4. 7. a positive charge in an atom
  5. 8. a neutral charge in an atom
  6. 9. the vertical columns in the periodic table
Down
  1. 2. electron that can be used in other atoms
  2. 3. multiple atoms together
  3. 5. a small particle that makes up every matter
  4. 7. the horizontal rows in the periodic table