In a compound the atoms of element 'Y' forms ccp lattice and those of element X occupy `2/3` rd of tetrahedral voids. What is the formula of compound ?

Explanation

Number of y atoms per unit cell = 4
Number of tetrahedral voids = 8
Number of tetrahedral voids occupied by `x=(2)/(3)xx 8=(16)/(3)`
Hence, formula of compound = x : y
`(16)/(3):4` or 16 : 12 or 4 : 3 Hence compound is `x_(4)y_(3)`