Write the chemical equations of heating of Cu and Fe.

Metal + oxygen $\stackrel{Heating}{\to }$ Metal oxide

Heating of Cu in presence of air -
2Cu(s) + O₂(g) $\stackrel{Heating}{\to }$ 2CuO(s)

Heating of Fe in presence of air-
4 Fe(s) + 3 O₂(g)  $\stackrel{Heating}{\to }$  2 Fe₂O₃(s)