Chapter 4, Problem 33P

(a)

Interpretation Introduction

Interpretation:

The crystal spacing should be calculated.

Concept Introduction:

The diffraction at a solid surface is calculated as follows.

  $\begin{array}{l}n\lambda =2a\sin \theta \\ n=\text{ plane number}\\ \lambda \text{= wavelength}\\ a\text{ = crystal spacing}\\ \theta \text{ = angle of diffraction}\end{array}$

(b)

Interpretation Introduction

Interpretation:

The diffraction angle for 90 eV electrons on the same surface should be calculated.

Concept Introduction:

The diffraction at a solid surface is calculated as follows.

  $\begin{array}{l}n\lambda =2a\sin \theta \\ n=\text{ plane number}\\ \lambda \text{= wavelength}\\ a\text{ = crystal spacing}\\ \theta \text{ = angle of diffraction}\end{array}$