Chemistry - Solid State Question with Solution | TestHub

In a CCP lattice, the number of atoms per unit cell is $4$.

Number of atoms of A $=4$

The number of octahedral voids is equal to the number of atoms in the lattice, which is $4$.

The number of tetrahedral voids is twice the number of atoms in the lattice, which is $8$.

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

Number of atoms of B $=4+\frac{1}{2}\times 8=4+4=8$

The ratio of atoms of A to atoms of B is $4:8=1:2$.

The formula of the solid is ${\text{AB}}_2$.

Answer: ${\text{AB}}_2$