Question

The edge length of fcc cell is 508 pm. If radius of cation is 110 pm, the radius of anion is

• A. 110 pm
• B. 220 pm
• C. 285 pm
• D. 144 pm

Answer 1

Answer: (D)

144 pm

Answer 2

For fcc,

$2(r_{+} + r_{-}) = a$

$2(110 + r_{-}) = 508$

$r_{-} = \frac{508}{2} - 110 = 144pm$