Question

The number of atoms in a simple cubic unit cell are :

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

Answer: (A)

Number of unit cell in simple cubic $=1$ atom/ unit cell
$8$ (at corners) $\times \frac{1}{8}=1$ atom
Body centered cubic $=2$ atoms/unit cell
($8$ at comers) $\times \frac{1}{8}+1$ (at body centre) $\times 1=2$ atoms
face centered cubic $=4$ atom/unit cell
$=8$ (at corner) $\times \frac{1}{8}+6$ (at face centres $\times \frac{1}{2}=4$ atoms
face centered tetragonal $=4$ atoms per unit cell