Talk:Ionization energy

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This article needs a few examples...not just H....

terms are also used to describe ionization of molecules and solids, but the values are not constant because ionization can be affected by the local chemistry, geometry, and temperature.

Ionization energies decrease down a group of the Periodic Table, and increase left-to-right across a period. These trends are exact opposite of the atomic radius periodic trends. Electrons in smaller atoms are attracted more strongly to the nucleus, therefore the ionization energy is greater. In larger atoms, the electrons are not held as strongly so the required ionization energy is lesser.

It also needs all the units defined it is rather hard to figure out what all the little units are partiularly the more isoteric ones used only in particle physics —Preceding unsigned comment added by Sponzyparadox (talk • contribs) 01:59, 5 December 2009 (UTC)[reply]

{{NPOV}} What's up with having a "A definition which is accepted for English A-Level exams" section? I don't even know what an English A-Level exam is. This is irrelavent. 20:49, 30 May 2006 (UTC)

There's a spelling error in the introduction of this article. It should be "bonded", rather than "bounded", I believe. For some reason I can't edit it.

I was reading the article and found "Particularly dramatic increases occur after any given block of atomic orbitals is exhausted, except when progressing to the next s orbital." Is it actually supposed to say that, or is that just a typo? In the event that it is supposed to say that, perhaps some sort of explanation as to what an s orbital is could be given to us shmucks out here? Much appreciated. 205.233.121.29 23:14, 8 March 2007 (UTC)[reply]

Although I am not able to put the phrase to layman's terms, the page on atomic orbitals will help. Starhood` 17:50, 2 April 2007 (UTC)[reply]

If I understand the text correctly, the variable n in the section titled `Electrostatic explanation' has been used for two completely different quantities: First as the charge of the ion (+ne), and later on as the angular momentum number (n hbar). I am no expert on this matter, and I might be wrong, but I don't think that these two quantities necessarily equate to each other. For instance, you could have an electron in a hydrogen atom (ie, an electron around a proton, +ne = +1e) in an excited state, ie, in some shell with n > 1 in the Bohr model. Could someone more knowledgeable on this topic verify (or refute) this claim, and correct the text if necessary? 69.235.145.252 22:13, 1 April 2007 (UTC)[reply]

It's not explained very well, but it is the same n. 150.203.35.113 (talk) 06:35, 15 July 2008 (UTC)[reply]

Can somebody maybe briefly explain the difference between vertical and adiabatic ionization potential? Personally, I would be interested to know which of the two is generally measured experimentally... —The preceding unsigned comment was added by 131.169.252.37 (talk) 08:46, 16 May 2007 (UTC).[reply]

A new section on this topic has finally been added today by user 220.227.207.32. This is a good start but there are a few problems. First the text is too closely copied from the source document, which may be a copyright violation. It needs to be rewritten. I have started by fixing some minor English errors which were surprisingly numerous for a NIST document.

Also the text refers to a Figure which is only found in the source document and not in the Wikipedia article. Either the figure should be redrawn (to avoid copyright problems), or else the text modified to eliminate reference to a figure which is not in the article. Dirac66 (talk) 15:33, 16 July 2009 (UTC)[reply]

The last part of this article is refered to a picture. Where is the picture ? [Above comment and question by Stepanhr 12:07, 22 Jan 2011]

I have moved the previous comment added today into this section, where I explained 18 months ago that the figure (or picture) is in the source document on which this paragraph is based - click on reference 2 to see it. As I said then, the figure should be redrawn in the article and the text should be rewritten. I will try to do this soon, unless someone else gets to it first. Dirac66 (talk) 19:23, 22 January 2011 (UTC)[reply]

I have found an appropriate diagram in the article Franck-Condon principle, which considers the analogous vertical and adiabatic (though not called that) transitions for electronic excitation. It can be inserted in this article along with a modified text. Dirac66 (talk) 02:54, 24 January 2011 (UTC)[reply]

If a chart of these first ionization energy can be provided in this page it would be more useful

Thank you

Shenya —Preceding unsigned comment added by 124.43.44.168 (talk) 13:45, 22 December 2007 (UTC)[reply]

Physically, the ionization potential is defined for a single unit, as pointed out by Itub. Check out the graphic: that's in eV, or O(10^-19) J. Like all energies, you are free to quote per mole if that rows your boat. Indeed, that's convenient for chemistry. Not for atomic physics, though. 150.203.35.113 (talk) 06:28, 15 July 2008 (UTC)[reply]

I think it should mention that ionization energy is always given for the element's gaseous phase/state. The definition is partial. Anyone agree?

1.Does ioninization energy increase down the periodic table? 2.does ionization energy decrease from left to right across the periodic table? 3. is it correct to define ionization energy as the energy needed to remove the most loosely bound electron from its ground state? —Preceding unsigned comment added by 193.220.62.5 (talk) 10:54, 24 October 2008 (UTC)[reply]

mathematical expression of conservative force —Preceding unsigned comment added by 193.219.222.125 (talk) 10:59, 24 October 2008 (UTC)[reply]

Since as stated in the first paragraph, the name "ionization energy" is now strongly preferred, is there any good reason for retaining the old-fashioned term "Ionization potential" as the article title? I propose that the article be moved to (wikispeak for renamed) "Ionization energy". Of course the existence of the older term should still be mentioned in the text, but not as the article title. Dirac66 (talk) 00:03, 13 May 2009 (UTC)[reply]

I support the move. Do it. 71.172.117.99 (talk) 15:24, 21 May 2009 (UTC)[reply]

This section needs a reference... This definitely isn't original work and we need a reference so people can go and verify the derivation is correct, and look for more detail if necessary. I'm sure we could find a reference in some solid state physics book or something. —Preceding unsigned comment added by Sealbock (talk • contribs) 23:16, 7 May 2010 (UTC)[reply]

Note to user 198.125.176.180. The link you have posted today to the ADAS database leads to the homepage of their website, and I was unable to find the actual ionization energy values on their website. I tried searching for ionisation energy (with British spelling since it is a UK website) and found 19 pages including various student theses, which was not too helpful. I think it would be better to post a link to the page which actually leads into the ionization energy values.

And the See Also section of this article includes a link to Ionization energies of the elements (data page). Do the ADAS tables have more values than we already have? Dirac66 (talk) 21:09, 18 April 2012 (UTC)[reply]

Would people mind if I deleted the two final paragraphs from the introduction? I'd like to start from "The ionization energy is..." and go all the way to the end of the intro "...proportional to (z-1)^2..." I find them exceedingly hard to follow and am not quite sure what they are trying to say. Specifically, here are some of the problems I have: 1) I don't fully agree with the statement that "ionization energy" is different for electrons of different atomic or molecular orbitals. In my experience, the adiabatic ionization energy (the minimum energy required to remove an electron) is the only one that really matters. The only reason vertical ionization energy is often measured for molecules is because it is often easier and less ambiguous to identify, whereas the adiabatic ionization energy is often difficult to determine, particularly when ionization results in a large displacement of the nuclear coordinates. Similarly, removing an electron from an orbital other than the HOMO (or equivalent) is just the adiabatic ionization energy of the atom/molecule plus the excited-state term energy of the newly-created ion. 2) Mentioning the idea of first, second, third, etc. ionization energies is essential for the intro, but as written it is quite hard to follow. It might be easier to rewrite from scratch. 3) I don't really like how eBE is being limited to cases of surface adsorption. In my experience, electron binding energy is used as a more general term for ionization energy that can refer to species other than gas-phase neutral or cationic species. Maybe we can replace this with a short paragraph describing analogs to ionization energy to other phenomena such as eBE, detachment energy, work function, etc. What do people think? Sirsparksalot (talk) 16:30, 12 January 2013 (UTC)[reply]

I agree and suggest moving paragraphs 2 and 3 of the intro down into the body. Intro para 2 could be worked into the adiabatic/vertical discussion for example. --Kkmurray (talk) 21:14, 12 January 2013 (UTC)[reply]

Would anyone mind if I removed the section on the "quantum explanation"? In my opinion, it doesn't really explain anything. The closest that it comes to doing so is in the final sentence where Koopman's theorem is mentioned. Personally, I think that the preceding section on "electrostatic explanation" is sufficient. Although, I would like to eventually rework that section and scale it down a bit. Sirsparksalot (talk) 00:21, 25 February 2013 (UTC)[reply]

I would prefer that we remove the "Electrostatic explanation" based on the Bohr model of the atom which has been obsolete since the Schrodinger equation was proposed in 1926. The "quantum explanation" is essentialy correct but too brief. What we have should be retained and expanded to provide better explanations. Dirac66 (talk) 01:45, 25 February 2013 (UTC)[reply]

• Keep both. Obsolete physics is still appropriate for an encyclopedia. QM should be expanded. Glrx (talk) 00:26, 26 February 2013 (UTC)[reply]

I suppose I meant that I don't think the QM section doesn't really provide an explanation of what ionization energy is. As far as I can tell, all it does is discuss how QM can be used to calculate a particular ionization energy. As such, I would still be in favor of removing it. If people insist on keeping it, I would suggest changing the section title to more apropriately reflect the topic. Sirsparksalot (talk) 20:53, 22 March 2013 (UTC)[reply]

Actually, now that I read through it again, I might see why it was originally included. Is the QM section meant to outline how ionization energies are dependent upon correlation terms? If so, can the section be simplified, rather than expanded, to state that these important correlation terms are in addition to the electrostatic attraction of the electron/nucleus and repulsion of electron/electron? Either way, I suppose I would stray from a lengthy discussion of the QM since correlation effects are discussed at length elsewhere. Could they just be mentioned then linked to? Sirsparksalot (talk) 20:58, 22 March 2013 (UTC)[reply]

i found two formulas for obtaining the last & penultimate IEدکترغلامعلی نوری Dr Goal.A. Newray 14:15, 26 August 2015 (UTC) — Preceding unsigned comment added by غلامعلي نوري (talk • contribs)

The latest edit by SahaArnab reminds us that some sources refer to (molar) ionization enthalpy rather than (molar) ionization energy. However they are not really identical since ΔH – ΔU = Δ(PV) ≈ RT Δn(gas) ≈ RT(+1) ≈ 2.5 kJ/mol, as an estimate if the atom, cation and electron are supposed to be ideal gases. Not accurate of course, but sufficient to indicate that the difference between ΔH and ΔU is not negligible compared to the values of ΔH and ΔU, so we should be careful to be distinguish between the two.

What I am not clear about, however, is whether the extensive tables of numerical values in this article and other articles are actually energies or enthalpies? Can someone answer this question, preferably with a reliable source, before we consider what to say about enthalpy in the article? Dirac66 (talk) 19:11, 26 January 2016 (UTC)[reply]

@Susan.grayeff:

You have cited a source as (in full) Reference- PCCP, 06.10.2016. I assume that PCCP is Physical Chemistry Chemical Physics, but could you please add the authors, title, volume and (especially) page numbers? Also if possible the DOI which makes it easier to find the paper on-line. I have never heard of the latent heat of the electron and would like to see what the authors of this paper are talking about. Dirac66 (talk) 22:34, 8 October 2016 (UTC)[reply]

No reply after 6 months so I have deleted the edit in question. I notice also that 10.06.2016 was in fact the date of the Wikipedia edit and not of the journal article, so the only information about the reference was "PCCP". It is not acceptable to cite only the name of a journal which publishes hundreds or thousands of articles per year. Dirac66 (talk) 18:25, 22 April 2017 (UTC)[reply]

I believe the constant ( 4* pi * permittivity of free space ) is missing in the Bohr radius explanation. Otherwise, there would be no way to arrive at the Rydberg constant value of 13.6 eV. — Preceding unsigned comment added by 24.35.94.49 (talk) 05:27, 20 April 2017 (UTC)[reply]

I have moved this new comment to the end of the talk page. The reason for omitting the factor 4πε₀ in the Electrostatic explanation is that this section uses old-fashioned Gaussian units, as noted in the first line of the section. No references are given, but presumably the derivation comes from an old textbook and is based on the original work of Bohr in 1913 which would have used Gaussian units. Modern SI units only came into widespread use about 1960.

However I agree that the explanation would be clearer to today's readers if it used SI units which include the factor 4πε₀, or perhaps if it gave the essential formulas in both sets of units. At the same time the section should be provided with references. Dirac66 (talk) 18:02, 22 April 2017 (UTC)[reply]

I feel like it would be helpful to mention something about the small mass defect associated with the atomic binding energy since most resources only mention the change in mass due to the nuclear binding energy. Does anyone have a good reference? — Preceding unsigned comment added by 173.180.46.190 (talk) 18:02, 2 May 2017 (UTC)[reply]

It seems to me there should be a link to "electron binding energy". Petedskier (talk) 12:55, 17 June 2018 (UTC)[reply]

"Electron binding energy" is not a separate article but directs to this article. However I will add a link to "Binding energy" which is a separate article. Dirac66 (talk) 00:03, 18 June 2018 (UTC)[reply]

Why do we need two different data pages for the ionization energies of the elements? As stated at the top of the section Values and trends, we have TWO Main articles: Molar ionization energies of the elements and Ionization energies of the elements (data page). There are slight formatting differences between the two, and one has values in both kJ/mol and eV. But I think it would be logical to merge the two data pages and have all the data for elemental ionization energies in the same article. Dirac66 (talk) 02:26, 15 August 2019 (UTC)[reply]

Yes I've asked that too. I think i put a motion of reconsideration in the molar data page, imma look. However i would really like to combine those two, to avoid unnecessary confusion. Ice bear johny (talk) 08:47, 11 September 2020 (UTC)[reply]

Hello! I've been searching google for umm maybe 1-2 hours, and I haven't found a reason why zirconium has a higher IE than titanium. Cannot blame the scandide contraction, nor low atomic radii (as zirconium has indeed a LARGER atomic radii than titanium).

In addition, if you have any leads (pun intended hehehe) for lead, please by all means, improve that part. I sadly cannot multitask, as October 5 (the day of doom aka online classes) is looming and I still have to pass an inane paper. Anyways thanks for all your help! Ice bear johny (talk) 03:09, 18 September 2020 (UTC)[reply]

The ionization energy derivation here is a special case and nearly the same analysis as in the Bohr model derivation. It's also given in Introduction to quantum mechanics and other places. Note also the Talk about units above. If you improve this section maybe coordinating with these other treatments will be helpful.

Would it serve well to cut the detailed derivation here and simply state the Bohr model results, leaning on that article for the derivation, and write the special case for ionization? Or does having it here in detail help? --MadeOfAtoms (talk) 03:04, 7 July 2021 (UTC)[reply]

I agree that the Bohr model has its own article so that the entire derivation does not need to be repeated here. So I have now deleted most of the section, leaving merely the H atom energy quoted from the Bohr model article plus the step from H atom energy to ionization energy. Dirac66 (talk) 00:18, 24 July 2021 (UTC)[reply]

Thanks Dirac66, looks good. --MadeOfAtoms (talk) 05:30, 24 July 2021 (UTC)[reply]