Chapter 11.6, Problem 1RCF

Interpretation Introduction

Interpretation:

The density of Lithium fluoride in FCC unit cell has to be calculated.

Concept Introduction:

FCC: In the face-centered cubic (FCC) cell, there will be six faces in a cube and the center of each face has a lattice point. Apart from the six faces, there will be eight corners. One corner atom will be shared by 8 unit cells and a face-centered atom is shared by 2 unit cells.

Density of Lithium fluoride:

$\text{Density}\text{=}\frac{\text{Mass}}{\text{Volume}}$

Relation between a (edge length) and V (volume) in FCC:

$\text{V}\text{=}{\text{a}}^{\text{3}}$

The relation between volume-V and edge length-a, enables to find the volume. Then mass has to be found out which can be divided by the calculated volume to determine the density.