Question

The volume of a crystal in BCC structure having N atoms is :

[a = edge length]

• A. $N_A{a}^3$
• B. $0.5N_A{a}^3$
• C. $0.33N_A{a}^3$
• D. $0.25N_A{a}^3$

Answer 1

The correct option is B $0.5N_A{a}^3$

The body-centred cubic (bcc) has a coordination number of 8 and contains 2 atoms per unit cell.

$V=\frac{N_A\times a^3}{Z}$

$Z=2\because \text{BCC structure}$

$V=\frac{N_A\times a^3}{2}$

$V=0.5N_A{a}^3$