Changes Around Us

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Across
  1. 4. the energy required to start a chemical reaction
  2. 5. the original substances present
  3. 6. a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change
Down
  1. 1. a change in which no new substance is formed
  2. 2. becoming more large or extensive
  3. 3. the new substances formed during or after the chemical reaction are known as products