The volume of atom present in a face-centred cubic unit cell of a metal (`r` is atomic radius ) is

Options

A. `(20)/(3) pi r^(3)`
B. `(24)/(3) pi r^(3)`
C. `(12)/(3) pi r^(3)`
D. `(16)/(3) pi r^(3)`

Answer

D

Explanation

volume of atoms in cell `= (4)/(3) pi r^(3) xx n ( :' n = 4 "for fcc")`
`= (4)/(3) xx pi r^(3) xx 4 = (16)/(3) pi r^(3)`