The metal calcium crystallises in fcc unit cell with a = 600 pm. Calculate the density of the metal if it contains `0.2%` Schottky defects.

Answer

`2.05"g cm"^(-3)`

Explanation

Due to Schottky defects, the number of atoms per unit cell will decrease.
`Z=(4-(4xx0.2)/(100))=(4-0.008)=3.992`
Density `(rho)=(ZxxM)/(a^(3)xxN_(0)xx10^(-30))`
`=((3.992)xx(40gmol^(-1)))/((600)^(3)xx(6.022xx10^(23)mol^(-1))xx(10^(-30)cm^(3)))`
`=2.05g cm^(-3)`