Question

The number of atoms contained in a $fcc$ unit cell of a monoatomic substance is

• A. 1
• B. 2
• C. 4
• D. 6

Answer 1

Answer: (C)

In a fcc unit cell, the number of corner atoms
$=8\times \frac{1}{8}=1$
( $\because$ Each corner is shared with 8 other unit cells) The number of face atoms
$=6\times \frac{1}{2}=3$
Thus, the total number of atoms per unit cell $=1+3=4$