What is the formula of a compound in which the element Y forms ccp lattice and atoms of X occupy `1/3`rd of tedrahedral voids.

Explanation

If n atoms of Y are involved in the formation of ccp structure, then number of tetrahedral voids in the Structure is 2n . Of the 2n tetrahedral voids, 1/3rd is occupied by X atoms. So, number of X atoms in the structure is `(2n)/3`.
Thus, the ratio of X and Y atom is `(2n)/2:n=2:3`. Hence, the formula of the compound will be `X_(2)Y_(3)`.