physical and chemical

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Across
  1. 2. reaction accompanied with release of heat
  2. 4. the process of depositing a layer of zinc on iron is called
  3. 6. is one that can reduce other substances by removing oxygen from them or by supplying hydrogen to them
Down
  1. 1. this is a chemical reaction that involves addition of oxygen or removal of hydrogen from a substance
  2. 2. evolution of gas is confirmed by appearance of
  3. 3. occurs in the presence of both oxygen and water
  4. 5. a solid in which atoms are arranged in a regular pattern