Chapter 3, Problem 3.35P

Interpretation Introduction

(a)

Interpretation:

In the closed packed hexagonal the number of atoms per unit cell is calculated.

Concept Introduction:

The closest hexagonal packed contains the coordination number of 12 has six atoms for each unit cell. The metals that has this kind of structure are gold, iridium, nickel, aluminum, copper, lead and silver having the packing factor of 0.74. The packing factor is calculated as follows:

  $\text{Packing factor}=\frac{\text{(volume per atom)(number of atoms of each cell)}}{\text{(unit cell volume)}}$

Interpretation Introduction

(b)

Interpretation:

Packing factor of the Mg unit cell should be determined.

Concept Introduction:

When the group of nucleons are brought together to form the nucleus atom, the net mass of gain and loss is measured gives the packing fraction.

The packing factor is calculated as follows:

  $\text{Packing factor}=\frac{\text{(volume per atom)(number of atoms of each cell)}}{\text{(unit cell volume)}}$

Interpretation Introduction

(c)

Interpretation:

The c/a ratio of magnesium and ideal HCP along with their slips should be compared.

Concept Introduction:

The cation to anion or c/a ratio is the ideal axial ratio for the structure of crystal hexagonal closed pack that is calculated by the identical spheres which are non-interacting and packed together.