Chemistry - PERIODIC TABLE Question with Solution | TestHub

$\mathrm{N}{\mathrm{a}}^{+}<{\mathrm{F}}^{-}<{\mathrm{O}}^{2-}<{\mathrm{N}}^{3-}$, All are isoelectronic species, hence effective number charge is highest for$\mathrm{N}{\mathrm{a}}^{+}$so it has smallest size.