Rusting of iron is an example of a redox reaction. It involves the oxidation of iron, where it loses electrons and reacts with oxygen to form iron oxide. The process is also accompanied by reduction, where oxygen gains electrons to form hydroxide ions. The overall reaction is:
Fe + 2H2O + O2 → Fe(OH)2
2Fe(OH)2 + 1/2O2 → Fe2O3.H2O (rust)
Therefore, rusting of iron involves both oxidation and reduction, which is the basis of redox reactions.