$A$ metal $M$ does not liberate hydrogen from acids but reacts with oxygen to give a black coloured product. Identify $M$ and the black coloured product,and also explain the reaction of $M$ with oxygen.

(N/A) The metal $M$ is Copper $(Cu)$.
Copper is less reactive than hydrogen in the reactivity series,so it does not displace hydrogen from dilute acids.
When copper is heated in the presence of oxygen,it undergoes oxidation to form Copper$(II)$ oxide $(CuO)$,which is a black-coloured substance.
The chemical reaction is:
$2Cu(s) + O_2(g) \rightarrow 2CuO(s)$ (Black product)