Talk:Principal quantum number

m0 undefined
Please define m0. is it m_e, the mass of electron ? — Preceding unsigned comment added by Fabrice.Neyret (talk • contribs) 09:43, 14 March 2019 (UTC)

Untitled
Aren't they the s, p, d and f orbitals? I'm confused. Jonathan Grynspan

s,p,d,f are for the orbital angular momentum (or azimuthal to give its ancient name) quantum number. I've put the vital word "average" in to qualify the distance of the electron from the nucleus - it is by no means fixed! --Ian 08:06, 30 Jan 2005 (UTC)

Radial quantum number
Why does radial quantum number redirect here? I have always been taught that the radial quantum number is:

$$ n_r = n - l - 1 $$

Being equal to the number of nodes in the radial wavefunction. Does wikipedia call this something else? --Zapateria 17:16, 6 June 2006 (UTC)

Tagged info on the radial quantum number onto the end of the article but think my formatting needs sorting out. Zapateria 17:48, 7 February 2007 (UTC)

wave/particle
I'm having trouble with the following line: ''The energy of any wave is the frequency multiplied by Planck's constant. This causes the wave to display particle-like packets of energy called quanta.''

There is no 'wave', nor any 'particle': there is just a quantum, namely the electron. We just visualize it as a wave or a particle, depending on the interaction it is undergoing, but it is neither! The fact that the electron has a certain energy does not cause it to do anything.

I know that the energy of an electromagnetic wave is equal to the frequency multiplied by Planck's constant. Does this hold for electrons? I vaguely seem to remember calculating the wavelength of a tennisball once... Even so, this just tells us the frequency from the (known) energy, it is not an explanation of quantization effects.

--GilHamiltonTheArm 14:21, 21 November 2006 (UTC)

Why were the Orbit shells Named "K,L,M,N,O..."?
I have to do a small research for my course about Why was it named K,L,M,N,O...., rather than A,B,C,D... , and i got quite lost while researching for it. —Preceding unsigned comment added by SherifHagar (talk • contribs) 16:43, 25 February 2010 (UTC)

Need an expert in this field to supply whatever is apparently missing from this sentence.
The following is the current second sentence in the introductory first paragraph. "As n increases, the electronic shells becomes more and the electron spends more time farther from the nucleus." Please fix. Thanks — Preceding unsigned comment added by 97.125.81.247 (talk) 18:47, 19 January 2016 (UTC)

Just a beginner trying to figure out how to notify of a small thing to add:
And, thanks so much for this article, clever helpful people who made it! Can we add complete definition of variables in Bohr's equation. So great to have this article! On a personal note, I'm note sure I've added a comment to this page in the right way...only just joined Wikipedia :)WikiStudent 23:34, 4 January 2020 (UTC) — Preceding unsigned comment added by Researchgatematerials (talk • contribs)

Elevator analogy seems out of place
Sometime in the past year (?) someone added an analogy to elevators in the intro: "For an analogy, one could imagine a multistoried building with an elevator structure. The building has an integer number of floors and a (well-functioning) elevator which can only stop at a particular floor. [...]" I think this metaphor is out of place, clumsy, and unhelpful. For example, the term "shell" is already invoking a better metaphor. A5 (talk) 19:44, 8 August 2018 (UTC)


 * OK I decided to remove it myself.A5 (talk) 21:11, 8 August 2018 (UTC)


 * I think the elevator analogy can be helpful as an introductory analogy. If you have some familiarity with quantum mechanics, it is a little clumsy, but this is a wikipedia page for a very basic QM concept, and I don't think we can assume all readers will be proficient in QM. It's a standard example used elsewhere: Astronomy Made Simple By Kevin B. Marvel, Ph.D. page 46:
 * "Electron energy levels are distinct, like floors on an elevator building. When riding in an elevator, you can get off only where a floor exists; you can't get off halfway between two floors. Similarly, electrons can exist only in particular orbits or energy levels, not in between."
 * Lasers by Hal Hellman, page 14:
 * "We  might   think   in   terms    of   an  elevator  that  can  only  stop  at  the  various  floors   of  an  apartment  building.  Each  upper   floor   is   like   an   orbit   of  the  electron.  But  you  get  nothing  for   nothing  in  the  world   of  physics,  and  just  as  it  takes  energy  to  raise  an  elevator  to  a  higher  floor,  it  takes energy  to  move  an  electron  to  an  outer  orbit."
 * I suggest we keep the elevator analogy, with a note that is in fact is not as rigorous as something like defining it formally as a good quantum number. Forbes72 (talk) 19:24, 3 October 2018 (UTC)

Principal quantum numbers give the number of main energy level
It is called quantum numbers 119.152.51.8 (talk) 18:16, 26 July 2022 (UTC)

Source of emission spectrum of an element
The "Derivation" section says "The difference between energy levels that have different n determine the emission spectrum of the element". Can emission lines not be generated by energy level changes with the same n, ie, within the same shell? See for example the image in Principal series (spectroscopy), which shows a 3p-3d transition. As I understand the notation, both states are in the same n=3 shell.

Certainly the difference between energy levels in different shells contributes to spectra, but that is not the sole source of spectra as this seems to suggest. Either "determine" is an overstatement, or "different n" is too restrictive. Perhaps "The difference between [available] energy levels determines the emission spectrum..."? Captain Puget (talk) 14:44, 2 May 2024 (UTC)