The fraction of volume occupied by atoms in a primitive cubic unit cell is nearly:

Options

A. 0.48
B. 0.52
C. 0.55
D. 0.68

Answer

B

Explanation

for simple cubic a = 2r
packing fraction ` = (1 xx 4/3 pi r^3)/(a^3) = (4/3 pi (a/2)^3)/(a^3) = pi/6 = 0.52`