Question

A cubic solid is made of two elements P and Q. Atoms of Q are at the corners of the cube and P at the body centre. What is the formula of the compound? What are the coordination numbers of P and Q?

Answer 1

As atoms Q are present at the 8 corners of the cube, therefore, number of atoms of in the unit cell = \(\frac{1}{8}\) × 8 = 1 

As atoms P are present at the body centre, therefore, number of atoms of x in the unit cell = 1 

∴ Ratio of atoms x:y =1:1 

Hence the formula of the compound is PQ coordination number of each of P and Q = 8.