Chemistry

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Across
  1. 3. Before a chemical reaction take place.
  2. 6. a stable subatomic particle with a charge of negative electricity
  3. 7. anything that has mass and takes up space.
Down
  1. 1. After a chemical reaction takes place
  2. 2. each side of the equation has the same number of atoms
  3. 4. a subatomic particle of about the same mass as a proton
  4. 5. a stable subatomic particle occurring in all atomic nuclei