Question

In a solid atoms 'P' are present at two face centers and atoms 'Q' are present at each corner of cubic unit cell. Formula of the crystal is .​

Answer 1

Answer:

Formula of the crystal is PQ.

Explanation:

In a cubic unit cell, face centre atom share with two cubic unit cell. So, participation of a face centre atom to a unit cell is 1/2. And corner atom share with 8 cubic unit cell.So, participation of a corner atom to a unit cell is 1/8.

Total number of P atom in a cubic unit cell = 1/2 ×2 = 1

Total number of Q atom in a cubic unit cell = 1/8 × 8 = 1

Formula of the crystal is P1Q1 i.e PQ.