Question

Total volume of atoms present in a face centred cubic unit cell of a metal is ($r$ is atomic radius):

• A. $\frac{20}{3}\pi r^3$
  
• B. $\frac{24}{3}\pi r^3$
  
• C. $\frac{12}{3}\pi r^3$
  
• D. $\frac{16}{3}\pi r^3$
  

Answer 1

The correct option is D $\frac{16}{3}\pi r^3$


Number of atoms in FCC $=4$
Hence, total volume occupied in FCC $=4\times \frac{4}{3}\pi r^3$
$=\frac{16}{3}\pi r^3$