Chemistry - Complete s-block Question with Solution | TestHub

Reactivity with water increases on moving down the Goup from $\mathrm{Li}$ to $\mathrm{Cs}$ as $\mathrm{Li}<\mathrm{Na}$ $<\mathrm{K}<\mathrm{Rb}<\mathrm{Cs}$. This is due to increase in electropositive character. Hence Rb reacts most vigorously with water.