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This very early FA needs improvement to keep its status; it has had two cleanup banners for years now, on citations and updates. The latter is especially troubling, with sentences such as "is expected to be largely depleted by 2021" and a lack of updates for issues such as conservation, the potential new molecular compounds, and applications usage. I will list this on WP:FARGIVEN, in case anyone wants to take it to FAR. ~~ AirshipJungleman29 (talk) 13:34, 25 March 2024 (UTC)[reply]
@AirshipJungleman29: I see that the clean-up banners are still on the page. Would you be interested in evaluating the article to see if the banners should be removed, or do you want to nominate this to WP:FAR? Z1720 (talk) 22:52, 26 May 2024 (UTC)[reply]
The classification into blocks is based on electron configurations, rather than chemical behaviour (except to the extent that the former relates to the latter). Double sharp (talk) 03:46, 23 September 2024 (UTC)[reply]
As far as I know, there is no consensus on the lanthanides and actinides being 0 to 13, or 1 to 14, f-electrons. Given that, is it obvious that p-block means 1 to 6, and not 0 to 5, p-electrons? CS people like to start counting at zero, but maybe chemists start at 1. Gah4 (talk) 00:43, 24 September 2024 (UTC)[reply]
The logic behind those (like me) who consider the f-block to start at La and Ac is not that we start at 0, but that La and Ac are really f1 elements who just happen to have an anomalous configuration in the atom (kind of like Cu d10s1 instead of d9s2), but who can correct that in chemical compounds (e.g. LaF3 has noticeable 4f valence contributions). In the other blocks, even that's not a problem. So both sides are counting from 1, and just disagree on what counts as 1.
In any case, if you wanted to count from 0–5 for some reason, the noble gases would all be s0 and hence s-block. I've not seen that idea since it became clear that noble gases do have (np) chemistry, though. Double sharp (talk) 02:49, 24 September 2024 (UTC)[reply]
Yes, at higher Z the rules are less obvious. The differences in energy levels are not so big. Well, that also gives the varying valence for transition metals. But the more usual question, is how to draw a nice periodic table. Which elements go in the rows below. And reminds me, it seems that there is question about Og being a noble gas or not. Gah4 (talk) 20:28, 24 September 2024 (UTC)[reply]
Normally the PT just gets drawn according to idealised valence configurations (i.e. assuming that the Aufbau held perfectly to Z = 118). Since this is always an excited state within the range of chemical bond energies, it tends to work fine (I don't know if it will be so past about 121, though). Exceptions sometimes happen for La and Ac (due to a long string of copying from when lanthanoid electron configurations were first wrongly thought to be 4f0-145d16s2 in general, rather than exceptionally; it was difficult in the 1920s and 1930s); and He (an almost universal exception, because hardly anybody likes putting helium with alkaline earths).
Og is not a noble gas in the sense that it's expected not to be particularly noble and might not be a gas at STP (if you could ever make enough and have it somehow not decay instantly). It is one in the sense that it's expected to be 7s27p6, making it formally fit group 18 even though its chemistry probably has more to do with Ge or Sn. But in general the issue for Cn through Og is that while the electron configurations formally fit Hg to Rn, the massive energy gap between 7p1/2 and 7p3/2 results in qualitatively different behaviour. Double sharp (talk) 03:18, 25 September 2024 (UTC)[reply]
By the way, would a split of energy level also occur eventually for d or f orbitals? If yes, it becomes significant from which principal quantum number? 129.104.65.7 (talk) 06:16, 26 September 2024 (UTC)[reply]
It already occurs in the known elements, but even at 5f and 6d it doesn't seem to create a qualitative change. Those series split more naturally into halves (7+7 and 5+5) than into 6+8 and 4+6. I don't think there are any good enough calculations of the 6f and 7d regions. :( Double sharp (talk) 06:32, 26 September 2024 (UTC)[reply]
The helium article should be edited in several places to correct the history of the observation of the line near D3.
"Helium was first detected as an unknown, yellow spectral line signature in sunlight during a solar eclipse in 1868 by Georges Rayet,[14] Captain C. T. Haig,[15] Norman R. Pogson,[16] and Lieutenant John Herschel,[17] and was subsequently confirmed by French astronomer Jules Janssen.[18] Janssen is often jointly credited with detecting the element, along with Norman Lockyer. Janssen recorded the helium spectral line during the solar eclipse of 1868, while Lockyer observed it from Britain. "
This text is almost entirely wrong and needs to be rewritten. Rayet's report in no way can be interpreted to conclude that he saw a new line near the D line; see the quotation given. Haig's report is relatively vague, and the colors given do not correspond to that of the D3 line (which is yellow). Pogson's unpublished report is ambiguous and non-quantitative; he could not rule out that the line he saw was the D line itself. And Herschel concluded that the line he saw WAS the D line, not a new line. Ascribing any portion of the discovery of the line Lockyer called D3 is wishful thinking. F
Also, the following sentences should be removed: "The line was detected by French astronomer Jules Janssen during a total solar eclipse in Guntur, India.[26][27] This line was initially assumed to be sodium. " Janssen did NOT report this line in his 1868 letter to the French Academy, and the cited references (Kochhar and Emsley) do not provide compelling evidence to the contrary. For better references, which conclude that Janssen did not see this line before Lockyer, see Launay F (2008) The astronomer Jules Janssen—a globetrotter of celestial physics. Springer, New York, p 45 and Lockyer JN (1868) Spectroscopic observations of the sun—No. II. Phil Trans Roy Soc (London) 159:425–444 as well as the footnote in the Wikipedia text that begins "In his initial report to the French Academy of Sciences" — Preceding unsigned comment added by 65.141.64.252 (talk) 15:38, 9 June 2024 (UTC)[reply]
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The helium article should be edited in several places to correct the history of the observation of the line near D3. The following text should be removed in its entirety: "Helium was first detected as an unknown, yellow spectral line signature in sunlight during a solar eclipse in 1868 by Georges Rayet,[14] Captain C. T. Haig,[15] Norman R. Pogson,[16] and Lieutenant John Herschel,[17] and was subsequently confirmed by French astronomer Jules Janssen.[18] Janssen is often jointly credited with detecting the element, along with Norman Lockyer. Janssen recorded the helium spectral line during the solar eclipse of 1868, while Lockyer observed it from Britain. "
Justification for above edit: Rayet's report in no way can be interpreted to conclude that he saw a new line near the D line; see the quotation given in ref [14]. Haig's report is relatively vague, and the colors given do not correspond to that of the D3 line (which is yellow). Pogson's unpublished report is ambiguous and non-quantitative; he could not rule out that the line he saw was the D line itself. And Herschel concluded that the line he saw WAS the D line, not a new line. Ascribing any portion of the discovery of the line Lockyer called D3 to any of these scientists is at best wishful thinking.
Also, the following sentences should be removed: "The line was detected by French astronomer Jules Janssen during a total solar eclipse in Guntur, India.[26][27] This line was initially assumed to be sodium. " Janssen did NOT report this line in his 1868 letter to the French Academy, and the cited references (Kochhar and Emsley) do not provide compelling evidence to the contrary. For better references, which conclude that Janssen did not see this line before Lockyer, see Launay F (2008) The astronomer Jules Janssen—a globetrotter of celestial physics. Springer, New York, p 45 and Lockyer JN (1868) Spectroscopic observations of the sun—No. II. Phil Trans Roy Soc (London) 159:425–444 as well as the footnote in the Wikipedia text that begins "In his initial report to the French Academy of Sciences" 192.17.85.116 (talk) 16:51, 5 November 2024 (UTC)[reply]
Tagged with an expert needed flag as seems quite niche. I don't think anyone uninvolved with chemistry will want to go against the multiple citations here. -OXYLYPSE (talk) 15:19, 25 November 2024 (UTC)[reply]
level-4 vital article is rated B-class on Wikipedia's content assessment scale.
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Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. (3OpenEyes's talk page. Say hi!) | (PS: Have a good day) 19:06, 5 January 2025 (UTC)