Giving appropriate examples (at least three), explain how the reactivity of a metal is related to its mode of occurrence in nature.

Explanation

(i) The values of high enthalpy of sublimation, high ionisation enthalpy, and low enthalpy of hydration for gold makes it almost inert. Thus, gold resists the action of most of the chemicals and is also unaffected by atmospheric condition. Hence, it occurs free in nature.
(ii) Iron being a highly reactive element is found in combined state. The reactivity if iron to get oxidised is also increased in presence of moisture and `CO_(2)`. Therefore, iron is never found in free state in nature.
(iii) Aluminium is a reactive metal. Hence, it is found in the combined state.