1. In an intense electron bombardment of the hydrogen atom, signi?cant electromagnetic radiation is pro- duced in all directions upon decay. Which emission line would you expect to be most intense? Why?
2. Why are peaks due to higher-lying excited states in the Franck-Hertz experiment not more observable?
3. As the voltage increases above 5 V in the Franck-Hertz experiment, why doesn't the current suddenly jump back up to the value it had below 5 V?
4. Using Hg gas in the Franck-Hertz experiment, approximately what range of voltages would you expect for the ?rst peak? Explain.