Semiconducting Devices Question 257
Question: Sodium has body centred packing. If the distance between two nearest atoms is $ 3.7{AA} $ , then its lattice parameter is
[Pb. PET 2002]
Options:
A) $ 4.8{AA} $
B) $ 4.3{AA} $
C) $ 3.9{AA} $
D) $ 23.3{AA} $
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Answer:
Correct Answer: B
Solution:
For bcc packing, distance between two nearest atoms $ d=2r=2( \frac{\sqrt{3}a}{4} ) $
Therefore Lattice constant $ a=\frac{2d}{\sqrt{3}}=\frac{2\times 3.7}{\sqrt{3}}=4.3{AA} $
