Answer:
wwe are asked to prive the atomic pavking factor APF for BCC is 0.68
solution
APF is given by equation (3.3) in the form
APF =nVs/Vc
whenn is the number of atoms per unit cell and for BCC n=2.0, Vs is the volume of the atom and it is given by 43π3³ and Vc is the volume of the unit cell and for BCC Vc=a³ where a is the side of the cube. From equation 3.4
we could get a by
a=4R/√3
where R is the radius of the atom. Now let us olug the expression inyo equation (1) to get APF
APF = nVs/Vc
=2.0(4/3πR³) / (4R/√3)³
=2.0(4/3πR³) / (4/√3)³ R³
=0.68