## Balmer and Rydberg series

H-Atom ($E_{n}=-\frac{hR}{n^{2}}$)

Ramya Natarajan 1D
Posts: 24
Joined: Fri Sep 29, 2017 7:04 am

### Balmer and Rydberg series

Hello all!
How exactly do the Balmer and Rydberg series differ from each other? Is the Balmer series only proven for H atoms, and if so, when would we even use it? Also, what does "n" signify in both these equations, spectral lines? Would "n" always be given in that case?

Naveed Zaman 1C
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Joined: Fri Sep 29, 2017 7:04 am
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### Re: Balmer and Rydberg series

The Balmer series is the set of lines formed through spectroscopy within a certain range of wavelength values. Figure 1.10 in the book shows it off better. Basically what we can take from that page in the book is that the Balmer series has the lower principal quantum number always at n1=2. This means that (in spectroscopy) when we analyze a hydrogen atom that has an electron that is excited, it will jump from the n=2 level to some other level. Eventually, the now unstable electron will come back down to the n=2 level, releasing light energy with wavelengths that lie somewhere in the Balmer series.

I think you're also referring to the Rydberg equation (there is no series), which shows us how to calculate the frequency of released light energy when we don't know the wavelength. In this case we look to what energy levels the electron jumps (thus n1 is where the electron starts and n2 is where the excited electron jumps to). The two topics are related, but one is a series (like a list or category) and the other one is an equation. Hope this helps!

Posts: 57
Joined: Fri Sep 29, 2017 7:04 am

### Re: Balmer and Rydberg series

From what I understood from the reading, the Balmer series is made up of lines in the visible spectrum. I'm assuming you mean the Lyman series, not the Rydberg series (because there was only mention of a Rydberg constant in the book). The Lyman series is made up of lines in the ultraviolet spectrum. The changes in "n" in both these concepts refers to the changing of an electron from one energy level to another.

Humza_Khan_2J
Posts: 56
Joined: Thu Jul 13, 2017 3:00 am

### Re: Balmer and Rydberg series

You say that as the excited electron goes back to n=2 it will "releas[e] light energy with wavelengths that lie somewhere in the Balmer series," but isn't there only supposed to be one wavelength of light for these transitions? Or do the Balmer series lines represent all the transitions from n=4, n=3, etc to n=2?