Why are the metals like Na, K, Ca and Mg never found in their free state in nature?

Q. Assertion :Metals like Na, K, Ca and Mg are never found in their free state in nature. Reason: Metals are very reactive elements. So, it combine with other non metal to complete its octet. Metals like Na, K, Ca and Mg are never found in their free state in nature.

Q. Give reasons:
(a) Metals like $\text{Na, K, Ca}$ and $\text{Mg}$ are never found in their free state in nature.
(b) Iron loses its lustre over time whereas gold does not.

Q. Metals at the top of the reactivity series $K,Na,Ca$ are never found in nature as free elements.

Q.

Question 61
Explain the following:

(a) Reactivity of $\text{Al}$ decreases if it is dipped in ${\text{HNO}}_3$.
(b) Carbon cannot reduce the oxides of $\text{Na}$ or $\text{Mg}$.
(c) $\text{NaCl}$ is not a conductor of electricity in the solid state whereas it does conducts electricity in aqueous solution as well as in molten state.
(d) Iron articles are galvanised.
(e) Metals like $\text{Na, K, Ca}$ and $\text{Mg}$ are never found in their free state in nature.

Q. A metal never found in free state is: