A binary silod`(A^(+) B^(-))` has a zine blende stracture with B inos consititating the lattice and `A^(+)` inos occupyiong `25%` of the terahedral holes. The formula of the solid is

Options

A. AB
B. `A_(2)B`
C. `AB_(2)`
D. `AB_(4)`

Answer

C

Explanation

Suppose no. of `B^(-)` ions constituting the lattice = 100
`:.` No. of tetrahedral sites = 200
As 25% are occupied by `A^(+)` ions their no. = 50.
`:.` Ratio of `A^(+):B^(-)=50:100=1:2` , i.e., the formula is `AB_(2)` .