A solid between `A` and `B` has the following arrangement of atoms `:`
`(i)` Atoms `A` are arranged in `c.c.p.` array.
`(ii)` Atoms `B` occupy all the octahedral voids and half the tetrahedral voids. What is the formula of the compound ?

Explanation

We know that in a close packing, the number of octahedral voids is equal to the number of atoms and number of tetrahedral voids is twice the number of atoms. As all the octahedral voids and half the tetrahedral voids are occupied, this means that :
(i) there will be one atom of B in the tetrahedral void
(ii) there will be one atom of B in the octahedral void.
Thus, there will be two atoms of B corresponding to each atom of A. Hence, the formula of solid `=AB_(2)`.