Question

Among the first four alkali metals in group l of the periodic table Li, Na, K, Rb the most electropositive metal is which one? Why?

Answer 1

Tendency of atoms of an element to lose electrons and form positive ion is known as electropositivity.

A more electropositive element has more metallic character.
On going along a group from top to bottom, the metallic character of elements increases.

Electropositive and Metallic character: Increases down a group
Li < Na < K < Rb < Cs

So among the first four alkali metals, Rb is more electropsitive.