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

Options

A. `(20)/(3) pir^(3)`
B. `8pir^(3)`
C. `4pir^(3)`
D. `(16)/(3)pir^(3)`

Answer

D

Explanation

For fcc, `Z_(eff) = 4//"unit cell"`
Volume of atoms in the unit cell `= 4/3 pir^(3) xx Z_(eff)`
`= 4/3 pi r^(3) xx 4`
`= (16)/(3) pir^(3)`