The Franck–Hertz experiment confirmed Bohr's quantized model of the atom by demonstrating that atoms could indeed only absorb (and be excited by) specific amounts of energy (quanta).
I saw only one specific energy level of gas molecule used in the experiment, which is the first excited state of the molecule. Why does my book say this experiment results shows that an atom only have specific energy in different energy levels, and the stable energy levels of atoms are discrete? I think this only proves 'at least one energy level in an atom is discrete.'
- 天同Lv 79 years agoFavorite Answer
The Frank-Hertz experiment was the poineer, but not the only experiment to verify that energy levels are discrete. There were a series of experiments to follow (you wouldn't expect a high school physics texbook to describe in detail all these experiments, would you?)
You could read the following web-page which gives a description of the Frank Hertz Experiment.
Notice the description "....Other arrangements for connecting the acceleration voltage permit measuring the ionization potential of mercury, and searching for higher energy levels of the mercury atom...." in the text.