Which of the following species will have the largest and the smallest size `Mg, Mg^(2+), Al, Al^(3+)`?

Explanation

Atomic radius decreases across the period . Here Mg and AI belong to the same period , so out of these two , Mg will have the farger size . Cation are smaller than their parent atoms due to higher effective nuclear charge. Among the isoelectronic species the one with a greater positive charge will have smaller radius . Hence we can say . out of Mg , `Mg^(2)`. AI and `AI^(3)` the largest size will be of Mg and smallest size is of `AI^(3)` .