A comound is formed by two elements M and N. The element N froms ccp and atoms of M occupy 1/3rd of tetrahedral voids. What is the formula of the compound ?

Answer

`M_2N_3`

Explanation

Since N forms ccp arrangement, it will have 4 atoms in a unit cell.
Number of N atoms in unit cell = 4
For each atom, there are two tetrahedral voids so that there are 8 tetrahedral voids per unit cell.
No. of M atoms = `1/3 xx 8 = 8/3`
Formula = `M_(8//3)N_4`
or `= M_2 N_3`.