Periodic table

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Across
  1. 5. The negative charge in an atom
  2. 6. valence electrons charge in an atom
  3. 8. The number of protons in a nucleus
  4. 9. The positive charge in an atom
Down
  1. 1. are the electrons on the outermost ring that determine an element's reactivity
  2. 2. the quantity of matter contained in an atom of an element
  3. 3. The different rows of elements
  4. 4. The different columns of elements
  5. 7. substance that cannot be broken down into smaller parts or changed into another substance.