Copper is heated in air and the surface turns black. The equation for the reaction is 2Cu+O2→2CuO2\text{Cu} + \text{O}_2 \rightarrow 2\text{CuO}2Cu+O2→2CuO. Which statement about this reaction is correct?
The copper is reduced because it gains oxygen.
The copper is oxidised because it gains oxygen.
The oxygen is oxidised because it gains copper.
The oxygen is reduced because it gains copper.
39 exam-style questions on AQA GCSE Chemistry 4.1 Reactivity of metals, covering 4.1.1 Metal oxides, 4.1.2 The reactivity series, 4.1.3 Extraction of metals and reduction, and 4.1.4 Oxidation and reduction in terms of electrons. Each one has a worked solution and a mark scheme showing where the marks go.