Hydrogen has only one electron, yet it exhibits multiple lines in a spectral series, why is this?

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    $\begingroup$ Have a look at this link and if that doesn't answer your question, consider editing your question to make it a bit more specific. The short answer is that the one electron can transition to/from multiple energy levels. $\endgroup$ Jul 3, 2013 at 16:01
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    $\begingroup$ Yeah, another man how didn't use google before asking a question here. Have your link en.wikipedia.org/wiki/File:Hydrogen_transitions.svg $\endgroup$
    – permeakra
    Jul 5, 2013 at 9:44
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    $\begingroup$ Related: codegolf.stackexchange.com/q/61371/45265 $\endgroup$
    – Jan
    Oct 22, 2015 at 15:44
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    $\begingroup$ This is a 6 year late reply: in response to @permeakra, a google search brought me here :) $\endgroup$ May 15, 2019 at 9:37

4 Answers 4


As the electrons fall from higher levels to lower levels, they release photons. Different "falls" create different colors of light. A larger transition releases higher energy (short wavelength) light, while smaller transitions release lower energies (longer wavelength).

The visible wavelengths are caused a by single electron making the different transitions shown below. There are even more transitions that release invisible wavelengths.

 Wavelength   Transition  Color              
 383.5384      9 -> 2    Ultra Violet
 388.9049      8 -> 2    Ultra Violet
 397.0072      7 -> 2    Ultra Violet
 410.174       6 -> 2    Violet
 434.047       5 -> 2    Violet
 486.133       4 -> 2    Bluegreen (cyan)
 656.272       3 -> 2    Red
 656.2852      3 -> 2    Red

*Values taken from Hyperphysics: Hydrogen Energies and Spectrum

(Why are there two different 3-> 2 transitions? See here: Hydrogen Fine Structure )


Though a hydrogen atom has only one electron, it contains a large number of shells, so when this single electron jumps from one shell to another, a photon is emitted, and the energy difference of the shells causes different wavelengths to be released... hence, mono-electronic hydrogen has many spectral lines.


Although hydrogen has only one electron, it contains many energy levels. When its electron jumps from higher energy level to a lower one, it releases a photon. Those photons cause different colours of light of different wavelengths due to the different levels. Those photons appear as lines. For this reason, though hydrogen has only one electron, more than one emission line is observed in its spectrum.


This arises due to the electron making transitions between the various energy levels in an atom . The electrons fall from a higher energy state to a lower energy state or vice versa emitting or absorbing wavelengths of different magnitude which fall directly on the spectrum of hydrogen thereby releasing colours of various wavelengths and creating a continuous spectrum .

  • $\begingroup$ Welcome to chemistry.se! If you have questions about how to beautify your posts, have a look at the help center. Do you want to know more about this site, please take the tour. || Referring to your answer: A line spectrum is of course not a continuous spectrum, as the title already says. $\endgroup$ Jan 16, 2015 at 7:17

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