Question

Aluminium crystallizes in fcca special substance which increase the rate of distillation

Answer 1

In a cubic close packed structure,the length of the side of unit cell is related to radius by an equation r = a/2√2

Or

a = r x 2√2

Putting the values in the equation,we get

a = 125 x 2 x 1.414 = 353.5 pm

Volume of the unit cell= (353.5 x 10-10)3 = 4.42 x 10-23

Number of unit cells in 1 cm3 = 1 / 4.42 x 10-23 = 2.26 x 1022unit cells.