Among the alkali metals caesium is the most reactive because

Options

A. Its incomplete shell is nearest to the nucleus
B. It has a single electron in the valence shell
C. It is the heaviest alkali metal
D. The outermost electron is more loosely bound than the outermost electron of the other alkali metals

Answer

D

Explanation

Alkali metals are highly reactive since they have a strong tendency to lose the single valence s-electron to from unipositive ions having inert gas configuration, In case of cesium, the distanceof the valence electron is maximum (among the alkali metals) so force of attraction by the nucleaus is least, hence it is most reactive.