Question

Sodium metal crystallizes in body centred cubic lattice with the edge length a=4.29. The radius of sodium atom is:

• A. $1.8574\stackrel{\circ }{A}$
• B. $2.8574\stackrel{\circ }{A}$
• C. $3.8574\stackrel{\circ }{A}$
• D. None of these

Answer 1

The correct option is A $1.8574\stackrel{\circ }{A}$

$R_{N{a}^{+}}=\frac{\sqrt{3}}{4}a$ (BCC lattice)
$=\frac{\sqrt{3}}{4}\times 4.29=1.857\stackrel{\circ }{A}$