Chemistry - PERIODIC TABLE Question with Solution | TestHub

Effective nuclear charge (i,e. Z/e ratio) decreases from ${\mathrm{F}}^{-}$ to ${\mathrm{N}}^{3-}$ hence the radii follows the order: ${\mathrm{F}}^{-}<{\mathrm{O}}^{2-}<{\mathrm{N}}^{3-}.\mathrm{Z}/\mathrm{e}$ for ${\mathrm{F}}^{-}=9/10=0.9,$ for ${\mathrm{O}}^{2-}=8/10=.8,$ for ${\mathrm{N}}^{3-}=0.7$