Question

Lithium metal crystallizes in a body- centered cubic crystal. If the length of the side of the unit cell of lithium is 351pm, the atomic radius of the lithium will be

• A. 300.5pm
• B. 240.8pm
• C. 151.8pm
• D. 75.5pm

Answer 1

The correct option is C 151.8pm

Edge Length $=351pm$. For bcc structure

$a\sqrt{3}=4r$

$r=\frac{a\sqrt{3}}{4}$

$=\frac{351\times 1.732}{4}=151.98$

$=151.8pm$