Sodium is more reactive than iron. How can you prove it?
(i) Sodium reacts vigorously with cold water and a large amount of heat releases but iron reacts with steam very slowly.
(ii) Sodium metal reacts with ferric oxide (Fe2O3) and forms sodium oxide by displacing iron.
6Na + Fe2O3 → 3Na2O + 2Fe
(iii) Sodium reacts with acids very quickly but iron takes some time to react with acids.