# Xenon crystallizes in face centre cubic lattice and the edge of the unit cell is 620 pm, then the radius of xenon-atom is

Q: Xenon crystallizes in face centre cubic lattice and the edge of the unit cell is 620 pm, then the radius of xenon-atom is

(A) 438.5 pm

(B) 219.20 pm

(C) 536.94 pm

(D) 265.5 pm

Solution : For fcc lattice

4r = √2 a    ; where a = 620 pm

or, $r = \frac{a}{2 \sqrt{2}}$

$r = \frac{620}{2 \sqrt{2}} pm$

r = 219.20 pm

Ans: (B)