Question

Sodium metal crystallizes in a BCC lattice having a unit cell edge of $4.29 \, Å$ . The radius of sodium atom is approximately:

• A. $0.93 \, Å$
• B. $1.86 \, Å$
• C. $3.22 \, Å$
• D. $5.72 \, Å$

Answer 1

Answer: (B)

For BCC,
$4r=\sqrt{3}a$
$r=\frac{\sqrt{3}}{4}a=\frac{\text{1.732}}{4}\times \text{4.29}$
$=\text{1.86 }\mathring{A} $