science

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Across
  1. 4. before a chemical reaction takes place
  2. 6. of mass: can not be created or destroyed
  3. 8. what is this unit
  4. 9. the year of the great discovery
Down
  1. 1. anything that has mass and takes up space
  2. 2. Lavoisier: a great discovery
  3. 3. all chemical equations must be this
  4. 5. cant be created or destroyed
  5. 7. after a chemical reaction takes place