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)

$26\%$ and $32\%$

Answer 2

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