A binary solid `(A^(+)B^(+))` has a rock sell structure .If the edge length is `400 pm` and radius of cation is 75 pm the radius of amion attion is

Options

A. 100 pm
B. 125 pm
C. 250 pm
D. 325 pm

Answer

B

Explanation

For NaCl type structure, distance between `A^(+)` and `B^(-)=(1)/(2)xx` edge length `=(1)/(2)xx400=200` pm .
As radius of cation = 75 pm, therefore , radius of anion `=200-75=125` pm