Chapter 3, Problem 3H.3BST

Interpretation Introduction

Interpretation:

Whether unit cell structure of iron is close-packed or body centered cubic has to be determined.

Concept Introduction:

Unit cell can represent lattice structure if it stacked together repeatedly with no gaps and rotations. This can also produce whole crystals by stacking method. Basic type of unit cells is as follows:

1. Simple cubic (SC).

2. Body centered cubic (BCC).

3. Face centered cubic (FCC).

Density of unit cell is as follows:

  $d=\frac{ZM}{a^3{N}_{\text{A}}}$        (1)

Here,

$Z$ is atoms in unit cell.

$M$ is molar mass.

$a$ is edge length of unit cell.

$N_{\text{A}}$ is Avogadro number.