Atoms of element B form hep lattice and those of the elements A occupy 2/3rd of tetrahedral voids. What is the formula of the compound formed by elements A and B.

Explanation

Let number of atom of B present in hep lattice =n
`therefore` Number of tetrahedral voids = 2n
Since only 2/3rd of tetrahedral voids are occupied by A,
Number of atoms of A present `=2/(3)xx2n=(4n)/(3)`
`therefore` Ratio of `B:A=n:(4n)/(3)=3n:4n=3:4`
`therefore` Formula of the compound : `B_(3)A_(4)orA_(4)B_(3)`.
`(because` element present in void generally forms cation).