A compound formed by elements `X` and `Y` crystallises in a cubic structure in which the `X` atoms are at the corners of a cube and the `Y` atoms are at the face centres.The formula of the compound is

Options

A. `XY_(3)`
B. `X_(3)Y`
C. `XY`
D. `XY_(2)`

Answer

A

Explanation

In unit cell, X- atoms at the comers `=(1)/(8)xx8=1`
Y-atoms at the face centres `=(1)/(2)xx6=3`
Ratio of X and Y = 1 : 3
Hence, formula is `XY_(3)`.