Periodic Table Crossword

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Across
  1. 4. The electron configuration of Hydrogen.
  2. 6. Mass number of Nitrogen.
  3. 7. Atomic mass of Helium .
Down
  1. 1. Atomic mass of Hydrogen.
  2. 2. Second element on periodic table.
  3. 3. The electron configuration of Helium.
  4. 5. H on the periodic table.