Calcium crystallizes in a face centred cubic unit cell with a = 0 .560 nm . The density of the metal if it contains 0.1% schottky defects would be:

Step-by-step solution

A face centred cubic unit cell contains four atoms. Schottky defect is basically a vacancy defect in ionic solids. Due to Schottky defects, the vacant spaces will increase, resulting in decrease in number of atoms per unit cell. Thus, number of atoms will reduce to: Z = 4 − 4 × 0.1 100 = 3.996 The density of the metal can be calculated by: ρ = Z × M N 0 × a 3 Where, M is the molecular mass of calcium = 40 g mol -1 N 0 is the Avogadro number = 6.022 × 10 23 mol - 1 a is the edge length = 0 .560 nm = 0 .56 × 10 − 7 c