Hard
When copper is heated in air, it reacts with oxygen to form a black coating of copper oxide. What type of reaction is this?
Explanation
Explanation
2Cu + O2 → 2CuO. Copper combines directly with oxygen from the air to form a single product, copper oxide, making this a combination reaction that is also an oxidation of copper.
PRO TIP
Re-check your working by substituting the answer back into the original question.