Chemical Changes

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Across
  1. 2. a system in which no matter is allowed to enter or leave
  2. 4. a material that releases energy when it burns
  3. 6. a biological catalyst that lowers the activation energy of reactions in cells
  4. 8. the minimum of energy needed to get a chemical reaction started
  5. 9. a rapid reaction between oxygen and fuel that results in the fire
  6. 10. the amount of one material in a certain volume
Down
  1. 1. a material that increases the rate of a reaction by lowering the activation energy
  2. 3. a reaction that releases energy in the form of heat
  3. 5. a material that decreases that rate of a reaction
  4. 7. a substance that enters into a chemical reaction