A compound formed by element `X` and `Y` crystallizes in the cubic structure when `Y` atoms are at the corners of the cube and `X` atoms are at the alternate faces. What is the formula of the compound?

Answer

`XY`

Explanation

There are 8 Y atoms at the corners and contribution of each is `1//8`.
`:.` No. of Y atoms per unit cell = `8 xx 1/8 = 1`
There can be only two X atoms at alternate faces and contribution of each of them is `1//2`.
`:.` No. of X atoms per unit cell = `2 xx 1/2 = 1`.
Hence , formula is XY.