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

As there are 8 Y atoms at the corners and contribution of each =`1/8`, therefore , no. of Y atoms/unit cell `=8xx1/8=1` . There can be only two X atoms on alternate faces. As contribution of each of them =`1/2`, therefore, no. of X-atoms/unit cell =`2xx1/2=1`. Hence, formula is XY