Energy changes

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Across
  1. 1. difference between energy transferred from surroundings and energy transferred to the surroundings
  2. 4. when you burn something
  3. 6. chemical that speeds up a chemical reaction but is not used up
  4. 7. release energy and get hot
  5. 8. need an acid and a base to form salt and water
  6. 9. energy required to break bonds - energy released by forming bonds
Down
  1. 2. shows if a reaction is exothermic or endothermic
  2. 3. absorb/take in energy and get cold
  3. 5. minimum energy needed to start a reaction