On exposure to air, alkali metals get tranished due to formation of oxides, hydroxides and carbonates on their surface. When heated in air or oxygen they burn vigourously forming different types of oxides depending upon the nature of the metal. The formation and stability of these metals can be explained on the basis of size of alkali metal ion and the anion. Peroxides are colourless, while superoxides are coloured. The normal oxides are basic while peroxides and superoxides act as oxidising agents.
`Na_(2)O_(2)` has light yellow colour. This is due to
A. Presence of traces of `NaO_(2)`
B. Presence of unpaired electron in the molecule.
C. Presence of traces of `Na_(2)O`.
D. None of the above.