A solid is formed of two different elements, A and B. In this atoms of A are arranged in the CCP array, and atoms of B occupy all octahedral voids and half of tetrahedral voids. Find the formula of the solid.

Step-by-step solution

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 + 1 2 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 AB ₂ . Answer: AB ₂