Science puzzle

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Across
  1. 1. A substance that is made with two or more elements
  2. 5. two words
  3. 7. Chemical process using electricity to break down compounds
  4. 8. The smallest unit of matter
Down
  1. 1. The amount of substance in a chemical reaction
  2. 2. Outcomes of a chemical reaction
  3. 3. A substance that only has one atom
  4. 4. The amount of atoms in a molecule
  5. 6. Group of atoms bonded together
  6. 9. Amount of matter in an object