Question

Metal like sodium potassium calcium and magnesium never found in their free state in nature

Answer 1

This is because these elements are very reactive.
They react with other elements like Oxygen, Nitrogen etc. and form compounds and are thus never found in free state.
Hope it helped.

Answer 2

Metal like sodium potassium calcium and magnesium never found in their free state in nature because they are reactive. They react with oxygen and water and form poisonous gases