A metal crystallizes with a face-centered cubic lattice. The edge of the unit cell is 408 pm. The diameter of…

3 2012 AIPMT-PRE The Solid StateCubic unit cells Easy
A metal crystallizes with a face-centered cubic lattice. The edge of the unit cell is 408 pm. The diameter of the metal atom is:
A 204 pm
B 288 pm
C 408 pm
D 144 pm

Detailed Solution

In an fcc lattice the atoms touch along the face diagonal: $\sqrt2a = 4r$
Diameter $= 2r = \frac{\sqrt2a}{2} = \frac{a}{\sqrt2}$
$2r = \frac{408}{1.414} = 288$ pm

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Practise Cubic unit cells All 3 questions This chapter in 2012 AIPMT-PRE