Frank-Hertz experiment with Neon

• Supervisor: Dr. Weifeng Su
• Location: Room 226-232， Henglong Physics Building

• To investigate the first excitation potential of neon, and to observe the light emission resulted from the de-excitation of excited atoms.

Lab 8 Franck-Hertz experiment

1. Atomic structure
2. Electron-molecular interaction

　　The Franck-Hertz experiment was a physics experiment that provided support for the Bohr model of the atom, a precursor to quantum mechanics. In 1914, the German physicists James Franck and Gustav Ludwig Hertz sought to experimentally probe the energy levels of the atom. The now-famous Franck-Hertz experiment elegantly supported Niels Bohr's model of the atom, with electrons orbiting the nucleus with specific, discrete energies. Franck and Hertz were awarded the Nobel Prize in Physics in 1925 for this work.

• Franck-Hertz power supply and tube (Neon)（Leybold Didactic）

• To observe the light emission
• Measuring the first excitation potential of neon

• From what phenomena in this experiment, we can conclude that the energy of electrons in an atom is quantized?
• Why is it necessary to apply a deceleration voltage between the collector electrode A and the anode grid G2?
• Discuss the reason(s) to why the current of the peaks and troughs of the curve increase when increasing the acceleration voltage U2.
• What is the wavelength of the light emission between the two grids? Is it the emission from the de-excitation process of neon atoms from the first excitation state to the ground state?

franck-hertz_experiment_with_neon.pdf