A compound is formed by two elements `X` and `Y`. Atoms of the element `Y` (as anion) make ccp and those of element `X` (as cation) occupy all the octahedral voids. What is the formula of the compound?

Explanation

Let the atoms of Y in ccp arrangement = n.
Since the number of octahedral voids is equal to the number of atoms in ccp arrangement,
`therefore" "` Number fo octahedral voids = n.
Since all the octahedral voids are occupied by atoms X
`therefore" "`Number of atoms of X = n.
Thus, atoms of two elements X and Y are in the same ratio,
Ratio of `X:Y=n:n=1`
The formula of compound = XY.