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### Rydberg Equation

Posted: **Sat Apr 21, 2018 7:50 pm**

by **Fiona Grant 1I**

I remember that in class, we did example where we found the frequency of light being emitted when an electron changes energy levels. In this example, we used the equation E = -hR/n^2 at each energy level and then subtracted them to find the frequency using E = hv. I understand how the Rydberg equation will yield the same answer, but we intentionally avoided using the Rydberg equation and were therefore not given the equation to use in class. However, I noticed that for homework problem 1.15, it is impossible to complete the problem without using the Rydberg equation. I was wondering when we can or should be using the Rydberg equation? Is it preferred that we use the method we did in class to complete these types of problems?

### Re: Rydberg Equation

Posted: **Sat Apr 21, 2018 7:50 pm**

by **Natalie Noble 1G**

I too am not sure what is expected of us, but just to be safe I would know the equation, since it was needed for a hw problem and we talked about it in our discussion sections. I would just know how to derive it from the equation he did give us in class ( E(n)=-Rh/(n^2) )

E(initial) = E(final)

E(n(initial) = E(n(finial)) + photon

-Rh/(n(initial)^2) = -Rh/(n(finial)^2) + hv

-R/(n(initial)^2) = -R/(n(final)^2) + v

v = -R/(n(initial)^2 + R/(n(final)^2

v = -R ( n(initial)^2 + (n(final)^2 )

I mean technically we can figure out the Rydberg equation using the equation given to us in class. I would use whatever method is best for the parameters we are given in the question.

### Re: Rydberg Equation [ENDORSED]

Posted: **Mon Apr 23, 2018 3:10 pm**

by **Chem_Mod**

Prof. Lavelle stresses not using the Rydberg equation because as stated above, you can derive it from the equation given to you in class. He would rather you had a conceptual understanding of where the Rydberg equation comes from than have you just plug and chug.

### Re: Rydberg Equation

Posted: **Mon Apr 23, 2018 7:59 pm**

by **Emma Leshan 1B**

If we find it faster and easier to use the Rydberg equation on a test or quiz, are we allowed to use it as long as we understand the concepts?