Question

Among the alkali metals $Cs$ is the most reactive because :

• 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. its outermost electron is more loosely bound than the outermost electron ofthe other alkali metals

Answer 1

The correct option is D its outermost electron is more loosely bound than the outermost electron ofthe other alkali metals

Among the alkali metals, $Cs$ is the most reactive because its outermost electron is more loosely bound than the outermost electron of the other alkali metals. This is due to the increase in distance between the outermost electron shell and the nucleus.