packing fraction of a unit cell is drfined as the fraction of the total volume of the unit cell occupied by the atom(s).
`P.E=("Volume of the atoms(s) present in a unit cell")/("Volume of unit cell")=(Zxx(4)/(3)pir^(3))/(a^(3))`
and `%` of empty space = `100- P.F.xx100 `
where Z= effective number of stoms in s cube .
r= radius of a an atoms
a = edge lenght of the cube
`%` of energy space in body centered cubic cell unit is nearly :

Options

A. 52.36
B. 68
C. 32
D. 26

Answer

C