Question

Assertion (A) The packing efficiency of hcp and $fcc$ arrangement is equal.
Reason (R) In hcp packing each sphere is surrounded by twelve other spheres.

• A. Both $A$ and $R$ are correct; $R$ is the correct explanation of $A$.
• B. Both $A$ and $R$ are correct; $R$ is not the correct explanation of $A$.
• C. $A$ is correct; $R$ is incorrect.
• D. $R$ is correct; $A$ is incorrect.

Answer 1

Answer: (B)

In $hcp$ as well as $ccp$ packing each sphere is surrounded by twelve other spheres. Thus, the packing efficiency of hcp and $fcc$ arrangement is equal.