Franck-hertz Definition and 16 Threads

In the experiment, I know that the spacing between successive valleys gives the excitation energy to be somewhere around 4.9eV. However, when you look at the plot, you can see that the spacing from zero to the first peak is much longer than any other spacings between two successive peaks. I was...

Homework Statement I have two questions concerning the Franck-Hertz experiment on Mercury. The first one is to explain the tops and dips in the voltage-current graph (https://en.wikipedia.org/wiki/File:Franck-Hertz_en.svg). The second question consider the experimental setup, and why there is...

Hi. I've recently conducted a Franck-Hertz experiment with mercury. I was able to see bluish glowing regions just as here: However, theory predicts 254 nm, which is far below visible. Are there other energy levels at play here? Wouldn't that mess up the 4.9-V-spaces of the drops in the current...

Hi. The blue curve shows the idealized behaviour of the detected current vs. the acceleration voltage in a Franck-Hertz experiment: It appears that the underlying behaviour is quadratic, why? I calculated the time for an electron to reach the grid at distance ##d## from the hot cathode to be...

Homework Statement In a Franck-Hertz experiment carried out with potassium vapour, it is found that the current falls off rapidly at an applied voltage of 1.62V. Calculate the wavelength of the expected spectral line in the emission spectrum of potassium when this voltage is reached. Homework...

My book gives the following graph for current vs accelerating potential for Franck and Hertz experiment (used to prove existence of discrete energy levels in atoms) using Mercury vapours in the tube: The book then writes: "Actually, atoms have more than one excitation potential and also an...

Hi In the FH experiment, what is physically happening when the excited mercury atom hits the metal plate? why does it induce a current drop? Thank you for any help :)

Homework Statement Hi! I'm writing my lab report on the Franck-Hertz experiment and I have trouble with the contact potential difference (inelastic collision). How do you calculate it? Homework Equations See below The Attempt at a Solution The energy differences between the maximum and...

As opposed to discrete values, given that the energy levels are discrete. The gas in mind here is helium. When studying the peaks a plot of accelerating voltage vs current that match up to the energy levels they should be discrete, right?

I have a question that might be very basic. The Franck-Hertz experiment shows that as the voltage (KE of the electrons) increase, the current/energy of the electron increases up to 4.9v at which point it drops due to the non elastic collision. this happens at intervals of 4.9v. assume that the...

Homework Statement As it is shown in the attached file,there is multiple maximums of the function. i understand that the first one (about 4,9V) corresponds to resonant line of the atom. What I don't understand is why the next one is higher than the first one, what does it mean...

I have to do a lab next week in which I repeat the Franck-Hertz experiment. I am reasonably sure that I understand most of what I need to do, but I'm just a little unsure on a couple of points, and would appreciate some guidance if anyone is knowledgeable with it. The instructions say that...

I'm studying the Franck-Hertz experiment for my Quantum Physics class, and I don't see why the minimums for the graphic U_1 (accelerating voltage) vs I_a (collector intensity) increase. It seems logical, but I can't find a proper explanation. If anyone could help me it would be great :)...

Homework Statement I've been given 2 values for the potential, 10.2 and 12.1V, I have to find the principle quantum numbers of which have been excited. The Attempt at a Solution I know En= -13.6/n^2 From there I'm stuck, I know it should go up in 4.9v, but 10.2 and 12.1 aren't multiples...

Homework Statement I've just done a practical to plot a franck-hertz curve for mercury. There are a few post-practical questions, and I'm not sure of 2 of them: 1) estimate the contact potential 2) estimate the mean free path of an electron in mercury vapour at a temperature of 160C and...

My questions are about the classic Franck-Hertz experiment where electrons are given energy by an accelerating voltage. These collide with mercury atoms, raising their internal energy. The electrons are then left with insufficient energy to overcome the retarding voltage of a collector plate...