What did the Franck-Hertz experiment prove?
In 1914, James Franck and Gustav Hertz performed an experiment which demonstrated the existence of excited states in mercury atoms, helping to confirm the quantum theory which predicted that electrons occupied only discrete, quantized energy states.
What is the effect of temperature in Franck and Hertz experiment?
Higher oven temperatures correspond to a denser Hg vapor and therefore a smaller mean free path for the electrons, reducing the probability of an electron navigating the thick Hg cloud.
What does the distance between the peaks or valleys represent in Franck-Hertz experiment?
If the observed current is plotted against voltage, the there will be a series of peaks and valleys. The peak-to-peak (or valley-to-valley) spacing will correspond to the excitation energy of the vapor (the multiple valleys are due to multiple inelastic collisions).
What really happens in the Franck-Hertz experiment with mercury?
The electron-mercury collision experiment of Franck and Hertz [1], for which they won the Nobel Prize in 1925, is one of the key experiments that helped to establish modern atomic theory. It shows that atoms can absorb energy only in quantum portions confirming Bohr’s postulates.
What inference is drawn Franck-Hertz experiment?
Conclusions from the plot of Franck and Hertz experiment Rising curve in the current v/s accelerating plot corresponds to region where the electron gain kinetic energy due to excitation potential but not enough to ionize the medium (mercury).
What is Franck Hertz data for neon?
The results for the neon implied that a lower energy transition was occurring within the neon atoms than is usually observed in the Franck-Hertz. This data was not consistent with the observed photon emission in the laboratory….
| Data Run # | Excitation Energy (eV) | Uncertainty |
|---|---|---|
| 12 | 17.266 | .12351 |
| Average | .55957 |
What is retarding potential Franck-Hertz experiment?
Description of experiment: a high collision probability. On the other hand, the separation between the anode and the collector electrode is small. Between the anode and the collector plate a small constant negative potential of 1.5 volt (“retarding potential”) is applied.
Why do we need to heat up the mercury in Franck-Hertz experiment?
The role of the oven is to heat the mercury in the vacuum tube, resulting in a large enough amount of mercury vapor in the tube such that an electron will suffer many collisions with mercury atoms as it moves between the cathode and anode.
What is contact potential in Franck-Hertz experiment?
For the Franck-Hertz tube the manufacturer indicates that the contact potential is about 2 V, which you will be able to verify with your measurements.
Which of the following can be used in Franck Hertz tube?
In the Franck Hertz Experiment the gas tube is filled with mercury vapors because they don’t react with free electrons.
What is the conclusion of Franck Hertz experiment?
James Franck and Gustav Hertz conducted an experiment in 1914, which demonstrated the existence of excited states in mercury atoms. It confirms the prediction of quantum theory that electrons occupy only discrete, quantized energy states.
What are the energy levels of mercury?
Atomic Structure
- First Energy Level: 2.
- Second Energy Level: 8.
- Third Energy Level: 18.
- Fourth Energy Level: 32.
- Fifth Energy Level: 18.
- Sixth Energy Level: 2.
How was the Franck Hertz experiment explained in terms of elastic?
The Franck Hertz experiment was explained in terms of elastic and inelastic collisions between the electrons and the mercury atoms. The graphs show the dependence of the electric current flowing out of the anode and the electric potential between the grid and the cathode. Following are the observations from the graph:
What did Franck and Hertz do?
Writing following the end of World War I in 1918, Franck and Hertz had largely adopted the Bohr perspective for interpreting their experiment, which has become one of the experimental pillars of quantum mechanics.
Who is the author of the Franck Hertz experiment?
Nicoletopoulos, who died in 2013, had authored and co-authored several papers related to the Franck–Hertz experiment; these papers challenge the conventional interpretations of the experiment. See Robson, Robert; White, Ronald.
What happens when electrons are accelerated in the Franck Hertz apparatus?
Electrons are accelerated in the Franck-Hertz apparatusand the collected current rises with accelerated voltage.