# Chapter 24: Atomic Physics

**At Grade**Created by: CK-12

A scanning electron microscope image of snow crystals, with computer-generated colors.

A scanning electron microscope is a tool that uses electrons to make very sharp images with magnification of up to 500,000x. Our knowledge of electrons comes from early study of the atom that lead to greater understanding not only of electrons and atomic structuer, but of the nature of all particles. This chapter covers modeling the atom and atomic spectra, the Bohr atom, and the Uncertainty Principle.

### Chapter Summary

1. The Balmer series is an empirical formula which gives the reciprocal of the wavelength \begin{align*}\lambda\end{align*}

\begin{align*}\frac{1}{\lambda}=R\left(\frac{1}{2^2}-\frac{1}{n^2}\right), n=3,4, \ldots\end{align*}

The letter \begin{align*}R\end{align*}

\begin{align*}R=1.097 \times 10^7 \ m^{-1}\end{align*}

The integer \begin{align*}n\end{align*}

2. Bohr quantized assumptions led to a more general statement of the Balmer series

\begin{align*}\frac{1}{\lambda}=R \left(\frac{1}{n^2_l}-\frac{1}{n^2_h}\right)\end{align*}

where \begin{align*}n_l\end{align*}

3. Bohr’s assumptions for hydrogen atom are:

a. The allowed radii of the atom

\begin{align*}r_n=n^2 r_1, n=1, 2, \ldots\end{align*}

where \begin{align*}r_1\end{align*}*Bohr radius*.

b. The allowable energy levels, or stationary states of the atom

\begin{align*}E=\frac{E_1}{n^2}, n=1, 2, \ldots\end{align*}

c. The difference between allowable energy levels can be expressed as

\begin{align*}hf=E_h-E_l\end{align*}

where \begin{align*}E_h\end{align*}

4. The square of the amplitude of the matter wave in Schrodinger’s equation assigns probabilities for the location of the electron.

5. The Heisenberg uncertainty principle is

\begin{align*}\Delta x \Delta p \ge \frac{h}{2 \pi}\end{align*}

where \begin{align*}\Delta x\end{align*}

### Image Attributions

**Save or share your relevant files like activites, homework and worksheet.**

To add resources, you must be the owner of the FlexBook® textbook. Please Customize the FlexBook® textbook.