<p>Actually, hydrogen can have as many electron levels as you want. However, they only exist at specific energy levels, with the potential energy given as:</p>

<p>$$E=-\frac{R_H}{n^2}$$</p>

<p>Where $R_h$ is the <a href="https://en.wikipedia.org/wiki/Rydberg_constant" rel="noreferrer">Rydberg constant</a>, and $n$ is any integer. When electrons are exited to a higher energy lever, they will fall back after some time and emit photons (not protons, by the way). So how many levels do they drop? Well, in the case of hydrogen, it will eventually go back to the basic energy level, but this is not guaranteed to happen in one jump. This may or may not take multiple jumps, that depends on probability. For a simple atom like hydrogen, those probabilities may be possible to calculate analytically. For more complex atoms however, this becomes an extremely difficult task, usually approached by simulations.</p>

CC BY-SA 3.0
2017-03-05T15:54:19.227Z
2017-03-05T15:54:19.227Z
SE - stop firing the good guys
<p>Electrons move to higher energy levels and drop back (electron migration). When they drop levels, photons are emitted and the wavelength/frequency emitted is based on how many levels are dropped. My question is, how does this work with elements with only one shell, such as hydrogen? Also, what determines how many energy levels are dropped?</p>

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2017-03-05T20:22:24.557Z
Hydrogen only has one *stable* "shell". Those don't emit light, of course - there's no less energetic configuration to drop down to. When you excite an electron, the whole point is that it ends up in a non-optimal energy configuration.
Luaan
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2017-03-06T13:34:14.790Z
As the answer points out, you're confusing *populated* shells with *available* shells.
Carl Witthoft
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2017-03-06T13:34:47.767Z
I'm voting to close this question as off-topic because it belongs on Physics.SE
Carl Witthoft
<light><spectroscopy><spectra>
How do elements with only one shell emit light?
user16090
# How do elements with only one shell emit light?

(Asked by: username_0 on 2017-03-05)

Electrons move to higher energy levels and drop back (electron migration). When they drop levels, photons are emitted and the wavelength/frequency emitted is based on how many levels are dropped. My question is, how does this work with elements with only one shell, such as hydrogen? Also, what determines how many energy levels are dropped?

**Tags:** light, spectroscopy, spectra
> **Comments:**
> **username_1**: Hydrogen only has one *stable* "shell". Those don't emit light, of course - there's no less energetic configuration to drop down to. When you excite an electron, the whole point is that it ends up in a non-optimal energy configuration.  
> **username_2**: As the answer points out, you're confusing *populated* shells with *available* shells.  
> **username_2**: I'm voting to close this question as off-topic because it belongs on Physics.SE  

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## 1 answers

### Answer by username_3 on 2017-03-05. Score: 4

Actually, hydrogen can have as many electron levels as you want. However, they only exist at specific energy levels, with the potential energy given as:

$$E=-\frac{R\_H}{n^2}$$

Where $R\_h$ is the [Rydberg constant](https://en.wikipedia.org/wiki/Rydberg_constant), and $n$ is any integer. When electrons are exited to a higher energy lever, they will fall back after some time and emit photons (not protons, by the way). So how many levels do they drop? Well, in the case of hydrogen, it will eventually go back to the basic energy level, but this is not guaranteed to happen in one jump. This may or may not take multiple jumps, that depends on probability. For a simple atom like hydrogen, those probabilities may be possible to calculate analytically. For more complex atoms however, this becomes an extremely difficult task, usually approached by simulations.


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