The number of atoms contained in one face -centred cubic unit cell of monoatomic substance is :

Options

A. 1
B. 2
C. 4
D. 6

Answer

C

Explanation

Face centred cubic is also called cubic close packed arrangement it has points at all the corners as well as at the centre of each of the six faces.
The number of atoms present at corners
per unit cell `=8xx(1)/(8)=1.`
The number of atoms presents at faces
per unit cell `=6xx(1)/(2)=3`
`therefore` Total number of atoms in ccp or
fcc arrangement = `1+3=4`