This simulator demonstrates how quantized atomic energy levels produce a measurable, macroscopic signature: regularly spaced dips in electron current as accelerating voltage increases, arising because mercury atoms can only absorb energy from colliding electrons in a single fixed amount corresponding to the gap between the ground state and the first excited state.
Increase the accelerating voltage gradually using the slider and watch the collector current respond. Note the voltage at which the first current dip appears, then continue increasing voltage to observe additional evenly spaced dips. Try adjusting vapor density, tube length, or gas type to see how these parameters change the sharpness or position of the dips.
Controls include an accelerating voltage slider (the primary control driving the experiment), a retarding voltage adjustment, mercury vapor density or tube temperature, tube length, and a gas selector to switch between mercury and neon, alongside a live current-versus-voltage graph that updates as the voltage sweeps.
Did you know the excited mercury atoms in a Franck-Hertz tube actually glow? As they relax back to the ground state they emit ultraviolet light at 253.7 nanometers, and in a real laboratory version of this experiment, faint glowing bands can sometimes be seen at the exact points along the tube where inelastic collisions are occurring.
This simulator demonstrates how quantized atomic energy levels produce a measurable, macroscopic signature: regularly spaced dips in electron current as accelerating voltage increases, arising because mercury atoms can only absorb energy from colliding electrons in a single fixed amount corresponding to the gap between the ground state and the first excited state.
This simulator demonstrates how quantized atomic energy levels produce a measurable, macroscopic signature: regularly spaced dips in electron current as accelerating voltage increases, arising because mercury atoms can only absorb energy from colliding electrons in a single fixed amount corresponding to the gap between the ground state and the first excited state.
Increase the accelerating voltage gradually using the slider and watch the collector current respond. Note the voltage at which the first current dip appears, then continue increasing voltage to observe additional evenly spaced dips. Try adjusting vapor density, tube length, or gas type to see how these parameters change the sharpness or position of the dips.
Did you know the excited mercury atoms in a Franck-Hertz tube actually glow? As they relax back to the ground state they emit ultraviolet light at 253.7 nanometers, and in a real laboratory version of this experiment, faint glowing bands can sometimes be seen at the exact points along the tube where inelastic collisions are occurring.