Chemistry - Complete s-block Question with Solution | TestHub

The stability of the oxide of alkali metals depends upon the comparability of size of cation and anion hence the main oxide of alkali metals formed with excess of air are as follows
Li ⇒$\mathrm{L}{\mathrm{i}}_2\mathrm{O}$(oxide)
Na ⇒$\mathrm{N}{\mathrm{a}}_2{\mathrm{O}}_2$(peroxide)
K ⇒$\mathrm{K}{\mathrm{O}}_2$(superoxide)
Rb ⇒$\mathrm{R}\mathrm{b}{\mathrm{O}}_2$(superoxide)
Cs ⇒$\mathrm{C}\mathrm{s}{\mathrm{O}}_{\mathrm{2 }}$(superoxide)