Question

What is the percentage of free space in $fcc$ and $bcc$?

• A. $32\%$ and $68\%$
• B. $68\%$ and $32\%$
• C. $26\%$ and $32\%$
• D. $32\%$ and $26\%$

Answer 1

Answer: (C)

Packing fraction of fcc $=74\%$
Empty space $=100-74=26\%$
Packing fraction of bcc $=68\%$
Empty space $=100-68=32\%$