Question

An ionic solid $A^{\oplus }{B}^{⊝}$ crystallizes as a fcc structure. If the edge length of cell is $508$ pm and the radius of anion is $144$ pm, the radius (in pm) of cation is :

• A. $110$
• B. $364$
• C. $220$
• D. $288$

Answer 1

The correct option is A $110$

In an FCC lattice,

$a=2(r^{+}+r^{-})$

$508=2(r^{+}+144)$

$r^{+}=110\text{pm}$

Hence, the correct option is $\text{A}$