The Solid State - Result Question 18
####18. A metal crystallizes with a face-centered cubic lattice. The edge length of the unit cell is 408 pm. The diameter of the metal atom is : [2012]
(a) $288 pm$
(b) $408 pm$
(c) $144 pm$
(d) $204 pm$
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Solution:
- (a) For $f c c$ structure, $\sqrt{2} a=4 r$
$ \begin{aligned} & \frac{\sqrt{2} \times 408}{2}=2 r \quad(2 r=\text{ Diameter }) \\ & \text{ Diameter }=288.5 \simeq 288 pm \end{aligned} $
