A compound is formed by two elements M and N. The element N forms ccp and atoms of M occupy 1/3rd of tetrahedral voids.

The ccp lattice is formed by the atoms of the element N.

Here, the number of tetrahedral voids generated is equal to twice the number of atoms of the element N.

According to the question, the atoms of element M occupy 1/3^rdof the tetrahedral voids.

Therefore, the number of atoms of M is equal to 2x1/3 = 2/3^rd of the number of atoms of N.

Therefore, ratio of the number of atoms of M to that of N is M: N =2/3: 1 = 2 : 3

Thus, the formula of the compound is M₂N₃.

Suppose the atoms N in the ccp  = n 

.'. No. of tetrahedral voids = 2n

.^. . No. of atoms M = 2n/3

.^. . Ratio of M : N = 2n/3 : n

Hence, the formula of the compound is M₂N₃.

Given: M occupy 1/3rd of tetrahedral voids 

To find : Formula of the compound = ? 

Calculation: 

The CCP lattice is formed by the atoms of the element N. Here, the number of tetrahedral voids generated is equal to twice the number of atoms of the element N.

The atoms of element M occupy 1/3rd of the tetrahedral voids.

Therefore, the number of atoms of M = 2 x 1/3 = 2/3  of the number of atoms of N.

Therefore, ratio of the number of atoms of M to that of N is M: N = 2/3:1 = 2:3

Thus, the formula of the compound is M₂N₃.