Question

The edge length of a face-centered cubic cell is 508 pm. If the radius of the cation is 110 pm, the radius (in pm) of the anion is :

• A. $288$
• B. $398$
• C. $144$
• D. $618$

Answer 1

The correct option is C $144$

As we know, for fcc, $r_c+r_a=\frac{a}{2}$
$\therefore$ $110+r_a=\frac{508}{2}$
$\therefore$ $r_a=144$ pm