Chemistry - Solid State Question with Solution | TestHub

In a face-centered cubic (fcc) unit cell, atoms are present at the $8$ corners and at the centers of all $6$ faces.

The atoms present at the face centers are shared equally between two adjacent unit cells. Thus, the contribution of each face-centered atom to one unit cell is $\frac{1}{2}$.

Number of faces in a cubic unit cell = $6$

Total number of atoms present on all faces per unit cell = $6\times \frac{1}{2}=3$ atoms.

Answer: $3$ atom