Question

The volume of atoms present in a face-centered cubic unit cell of a metal (r is atomic radius) is :

• A. $\frac{20}{3}\pi r^3$
• B. $8\pi r^3$
• C. $4\pi r^3$
• D. $\frac{16}{3}\pi r^3$

Answer 1

Answer: (D)

$\frac{16}{3}\pi r^3$

In a face-centred cubic unit cell, there are 4 atoms.
So the volume of atoms is $=\frac{4\times 4\pi r^3}{3}$

$=\frac{16}{3}\pi r^3$

Hence, the correct option is $\text{D}$