• # question_answer The size of the following species increases in the order [IIT-JEE 1990; AFMC 1995] A) $M{{g}^{2+}}<N{{a}^{+}}<{{F}^{-}}<Al$ B) ${{F}^{-}}<Al<N{{a}^{+}}>M{{g}^{2+}}$ C) $Al<Mg<{{F}^{-}}<N{{a}^{+}}$ D) $N{{a}^{+}}<Al<{{F}^{-}}<M{{g}^{2+}}$

$M{{g}^{2+}}<N{{a}^{+}}<{{F}^{-}}<Al$ ${{F}^{-}}$ has bigger size than $M{{g}^{2+}}$ and $N{{a}^{+}}$ due to small nuclear charge.