The correct sequence which shows decreasing order of the ionic radii of the element is

Options

A. `Al^(3+)gtMg^(2+)gtNa^(+)gtFgtO^(2-)`
B. `Na^(+)gtMg^(2+)gtAl^(3+)gtO^(2-)gtF^(-)`
C. `Na^(+)gtF^(-)gtMg^(2+)gtO^(2-)gtAl^(3+)`
D. `O^(2-)gtF^(-)gtNa^(+)gtMg^(2+)gtAl^(3+)`

Answer

D

Explanation

`O^(2-),F^(-),Na^(2+),Mg^(2+)` and `Al^(3+)` are isoelectronic species , for isoelectronic species , `r prop 1/Z`
Thus , the larger the atomic number (effective nuclear charge) the smaller is the ionic radii.