The percentage of empty space in a body centred cubic arrangement is :

Options

A. 74
B. 68
C. 32
D. 26

Explanation

For body centred cubic arrangement , `Z_("eff")=2`
Packing fraction (PF)
`=("Total volume of spheres")/("Volume of the unit cell")xx100`
`PF=(2xx3/4pir^3)/(((4r)/(sqrt3))^3)xx100 " " [ therefore " bcc hace two atoms"]`
`rArr PF=((8pir^3)/(3))/((64r^3)/(3^(3//2)))xx100=68%`
`therefore` Empty space = 100 - PF
= 100 - 68 = 32%