Question

 In a crystalline solid, the atoms A and B are arranged as follows :

 (a) Atoms A are arranged in ccp array.

 (b) Atoms B occupy all the octahedral voids and half of the tetrahedral voids.

 What is the formula of the compound ?

Answer 1

 No. of A (ccp) = 4

 No. of B = octahedral voids + Tetrahedral/2

=4+8/2

=4

A : B        therefore, formula of the compound is AB₂ 

4 : 8 

1 : 2

 AB₂