Rydberg Equation

[Racquel Fox 2I]

I know the Rydberg equation on the equation sheet is v=R[1/(n1^2) - 1/(n2^2)], but in one of the review sessions yesterday the equation En=-(hR)/n^2 was brought up. Can you derive the first equation from the second one, and if we had a question on the final asking about energy levels, which equation should we use?

[Kaley Qin 1F]

I think for the lecture we will only have the frequency equation for Rydberg's equation. So if we need to find the energy level of n, or the change in energy level, we can just use the equation that relates energy to frequency: E=hv.

[Andrew Wang 1C]

Yes, you can get the Rydberg equation by setting E=hv equal to the difference between energy levels -(hR)/n2^2 - (-(hR)/n1^2). then you cancel h from both sides to get the equation in the equation sheet. If they were asking you to calculate the energy of a specific level you'd probably use -(hR)/n^2, and use the equation on the sheet to find the difference between levels or the frequency/wavelength of light from changing levels.