Ncert Exercises & Solutions

Consider the isoelectronic species, ${Na}^{+}, {Mg}^{2 +}, F^{-}, and O^{2 -}$ . The correct order of increasing length of their radii is :

1. $F^{-} < O^{2 -} < {Mg}^{2 +} < {Na}^{+}$

2. ${Mg}^{2 +} < {Na}^{+} < F^{-} < O^{2 -}$