Question

Lithium forms body centred cubic structure. The length of the side of its unit cell is $351\, pm$. Atomic radius of the lithium will be :

• A. $75\, pm$
• B. $300\, pm$
• C. $240\, pm$
• D. $152\, pm$

Answer 1

Answer: (D)

$152\, pm$

Answer 2

For BCC structure $\quad\quad\sqrt{3}a = 4r$ $r = \frac{\sqrt{3}}{4}a\quad= \frac{\sqrt{3}}{4} \times351= 152 \,pm.$