Talk:Isotopes of hydrogen/Archive 1

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Archive 1

Half-lives

Some of the half-lives in the article were of dubious precision. I adjusted them according to above sources, until someone finds more specialized references. Femto 16:34, 19 November 2005 (UTC)

Also the half-lives are different than those on the pages for the specific isotopes, don't know which are the correct ones, but it has to be changed at either the specific pages or here. http://en.wikipedia.org/wiki/Hydrogen-5 http://en.wikipedia.org/wiki/Hydrogen-4

Half-life of the proton?

The table says that the half-life of the 1H atom is >2.8·1023 years. Does this refer to the proton decay? If yes, then the half-life should be updated since it is most probably >1032 years. If not, then it should be stated while a proton with a bound electron might have a shorter half-life than a naked proton. Or, if it simply indicates a lower border given be the experiments in the source, then this should also be made clear. Since the CRC Handbook Online is not a free source (you need a user login that seems to be given to selected people only) no one can expect the reader to retrieve the original source.--SiriusB (talk) 14:07, 23 June 2008 (UTC)

Merged H-5

It was a duplicate. Lanthanum-138 (talk) 04:37, 3 February 2011 (UTC)

Ions of Hydrogen-1?

Is it possible for the following to exist: A Hydrogen-1 atom that has become an ion by having one less electron? I.E. a free proton? Or does an atom always require at least one electron? What about a proton and two electrons? 87.194.8.35 (talk) 19:57, 27 October 2009 (UTC)

Yes. Both H+ and H- ions exist. XinaNicole (talk) 08:04, 25 May 2011 (UTC)

Hydrogen 6 Decay branches

All references to this indicate n and 3 n decay with 1 resource showing a 50/50 split in probability. I have not been able to find any evidence of a 4 n decay path. if anyone can cite for this it would be most appreciated. 74.202.23.198 (talk) 18:12, 22 July 2011 (UTC)

It's from the NUBASE97 paper, [1], pp. 14-15:

In the very special case of 6H we mention as possible decay channels 3 neutrons and 4 neutrons emissions. The reason is that, based on the observed mass values, both its Sn and S2n separation energies are positive, which makes it stable against 1 neutron and 2 neutron emission, but not against 3n or 4n emission. 6H decays with a half-life of 320(60) yoctoseconds. Its mass value is derived from two 7Li(7Li,8B) experiments and one 9Be(11B,14O). If this mass value is confirmed, 6H would be a unique laboratory for searching for simultaneous 3n or 4n emission.

But in NUBASE03 [2], the mass of 5H has been revised downwards, so according to this database, Sn(6H)<0. Spacepotato (talk) 02:20, 23 July 2011 (UTC)

Lose the column "decay energy"

You should add the column "decay energy" in the article "Isotopes of any chemical element! — Preceding unsigned comment added by 59.126.202.81 (talk) 16:21, 22 July 2012 (UTC)

too sharp?

Why is there a # sign in the 7H row in the last table? ("2.3(6)×10−23 s#") --TheAnarcat (talk) 18:23, 23 April 2013 (UTC)

See Notes (last section of article). The second note reads "Values marked # are not purely derived from experimental data, but at least partly from systematic trends." Dirac66 (talk) 18:49, 23 April 2013 (UTC)

Decay Chains Section

I would like to create a section on this article showing the complete decay chains of the isotopes (excluding theoretical proton decay for 1H and 2H). The basic draft is:

Jacob S-589 (talk) 23:54, 15 June 2014 (UTC)

Unbound isotopes

Many of the really heavy neutron-leaking isotopes of the light elements are actually unbound. Examples are 4–7H, 5He, 7He, 9–10He, 10Li, 12–13Li, 13Be, 15–16Be, 16B, 18B, 21C, 25–26O, 28F, 30F, 33Ne, 36Na, 39Mg. Double sharp (talk) 09:12, 26 June 2016 (UTC)

External links modified

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Exotic atoms

Why exactly is muonium mentioned in this article, and why only muonium and not also some other exotic atoms like positronium? —Preceding unsigned comment added by 84.194.236.251 (talk) 16:31, 15 September 2007 (UTC)

I also wonder why Muonium is mentioned here. Does Muonium have some special connection to isotopes of hydrogen?—Preceding unsigned comment added by 68.230.161.164 (talk • contribs) 20:29, 10 November 2007

Mu tends to act like a light isotope of hydrogen because the mass of the antimuon is significantly higher than that of the electron that is meant to be orbiting it. Ps behaves significantly differently. Double sharp (talk) 08:45, 18 May 2017 (UTC)

Does Tritium decay by Beta - or Beta +? Statue2 11:55, 8 October 2007 (UTC)

Where is Antihydrogen?Gordomono (talk) 05:00, 8 April 2009 (UTC)

Good suggestion. I have just added anti-H in a new subsection, with a link to the detailed main article. Dirac66 (talk) 16:11, 8 April 2009 (UTC)

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Untitled / original data (2005)

This article is part of Wikipedia:Wikiproject Isotopes. Please keep style and phrasings consistent across the set of pages. For later reference and improved reliability, data from all considered multiple sources is collected here. References are denoted by these letters:

  • (A) G. Audi, O. Bersillon, J. Blachot, A.H. Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003). — Where this source indicates a speculative value, the # mark is also applied to values with weak assignment arguments from other sources, if grouped together. An asterisk after the A means that a comment of some importance may be available in the original.
  • (B) National Nuclear Data Center, Brookhaven National Laboratory, information extracted from the NuDat 2.1 database. (Retrieved Sept. 2005, from the code of the popup boxes).
  • (C) David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes. — The CRC uses rounded numbers with implied uncertainties, where this concurs with the range of another source it is treated as exactly equal in this comparison.
  • (D) More specific level data from reference B's Levels and Gammas database.
  • (E) Same as B but excitation energy replaced with that from D.
  • (F) The references given for H4 are dead and provide no information. I have had multiple discussions with D.R. Tilley and H.R. Weller. Authors of Energy Levels of Light Nuclei A = 4. "ground state" at the nndc is the lowest energy lever at which something has been seen. For H-4 that is 4.6MeV after an 8MeV Pion hits Li-7. I will leave the final edit to someone with time to do so.
  Z   N refs symbol   half-life                      spin              excitation energy
  1   0 AB  |H-1     |STABLE                        |1/2+
  1   0 C   |H-1     |>2.8E+23 a                    |1/2+
  1   1 ABC |H-2     |STABLE                        |1+
  1   2 AB  |H-3     |12.32(2) a                    |1/2+
  1   2 C   |H-3     |12.33 a                       |1/2+
  1   3 A   |H-4     |139(10)E-24 s [3.28(23)MeV]   |2-
  1   3 B   |H-4     |[4.6(9) MeV]                  |2-
  1   3 C   |H-4     |[~3 MeV]                      |2-
  1   4 A*  |H-5     |>910E-24 s [<0.5 MeV]         |(1/2+)
  1   4 B   |H-5     |[5.7 MeV]                     |
  1   4 C   |H-5     |[1.9(4) MeV]                  |
  1   5 A   |H-6     |290(70)E-24 s                 |2-#
  1   5 BC  |H-6     |[1.6(4) MeV]                  |(2-)
  1   6 A   |H-7     |23(6)E-24# s [20(5)# MeV]     |1/2+#
  1   6 B   |H-7     |29(7)E-23 y [sic]             |

Femto 16:34, 19 November 2005 (UTC)

Update 2019

  • Now its 2019. Today this is:
A: {{NUBASE 2003}}: Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
B: Brookhaven {{NuDat 2}} aka {{NNDC}}: National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
C: {{CRC85}} Lide, David R., ed. (2004). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.
Other aged or outdated refs used
-DePiep (talk) 21:41, 27 June 2019 (UTC)

Unspecified tags, rm

In May 2018, LaundryPizza03 added two maintenance tags [3]. There was no specification, no post on Talk:Isotopes of hydrogen, and no contribution in this article by this editor before or after. Also, since serious contributions have been made since ([4]), I will remove these tags shortly for being unspecific and being addressed anyway. -DePiep (talk) 21:22, 27 June 2019 (UTC)

Removed [5]. ping @LaundryPizza03: -DePiep (talk) 15:13, 23 June 2021 (UTC)

AME and NUBASE values updated, minor formatting and citation issues

Hello everyone!

I've updated the AME and NUBASE values to the current 2020 values. However, I'm new here, and I'm not 100% sure how to add citations - can someone please properly cite AME2020 and NUBASE2020? If it helps, here's the original publications: [6]https://iopscience.iop.org/article/10.1088/1674-1137/abddaf (AME2020 II) and [7]https://iopscience.iop.org/article/10.1088/1674-1137/abddae (NUBASE2020).

I've also tried to fix up the isotope abundances of protium and deuterium in the table, but I've also accidentally messed up the table. Could someone please remove the range of variation column in the table?

I've also tagged the quadium claim as citation needed because there was no source next to it.
MeasureWell (talk) 08:13, 23 June 2021 (UTC)

@MeasureWell: In the #List of isotopes (big table) AME2020 II and NUBASE2020 are correctly added (through your editing |refs=NUBASE2020, AME2020 II Green tickY). Currently footnote numbers [7] and [8].
The same references can be entered using {{NUBASE2020|ref}} → [1] and {{AME2020 II|ref}} → [2] (see also documentation {{NUBASE2020}}). -DePiep (talk) 15:30, 23 June 2021 (UTC)

References

  1. ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. ^ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
Thanks! MeasureWell (talk) 01:18, 24 June 2021 (UTC)

Half lives of short lived isotopes

It is written in the article:

  • Hydrogen-4 has a half-life of 139(10) ys (or 1.39(10)×10−22 s).
  • Hydrogen-5 has a half-life of 86(6) ys (8.6(6)×10−23 s)
  • Hydrogen-6 has a half-life of 294(67) ys (2.94(67)×10−22 s)
  • Hydrogen-7 has a half life of 652(558) ys (6.52(5.58)×10−22 s) which is the shortest half-life known for any isotope of any element (see List of radioactive nuclides by half-life).

But Hydrogen-5 and Hydrogen-6 has according to this list shorter half life than Hydrogen-7.
In List of radioactive nuclides by half-life it is written:

  • hydrogen-4 139 ys (×10−24 s)
  • hydrogen-5 >91 ys (×10−24 s)
  • hydrogen-6 290 ys (×10−24 s)
  • hydrogen-7 23 ys (×10−24 s)

Mainly Hydrogen-7 do not match. And the used source periodictable.com is dead or down. Hydrogen-7 previously had 23 ys in the article but that was changed in this large edit of many numeric values--BIL (talk) 19:58, 20 August 2021 (UTC)

I have stumbled over this myself and decided to look into it. I have found the source only to find the link on this talk page afterwards. I blame not editing wikipedia for well over a decade for that.
If I am reading this right, the numbers in parentheses are the uncertainty. I will change the formating shortly to at least lessen the confusion for now, but it would be great if someone who had a better idea of both the subject and wikipedia could take a look at this and connected articles to clean it up properly. 2003:F0:8705:E921:35:4832:BA9E:6F88 (talk) 13:40, 3 September 2021 (UTC)
Done editing the numbers, but the text definitely needs someone else to check, especially as I do not have the time currently to also check the atomic mass numbers and their formatting. The Reference to Miessler may be outdated, I do not have that book accessible to check. The List of radioactive nuclides by half-life likely could also use someone more familliar with the matter taking a look at it. 2003:F0:8705:E921:35:4832:BA9E:6F88 (talk) 14:09, 3 September 2021 (UTC)
Hi, thanks for your comment. The parenthesized notation for uncertainty is standard practice for isotope pages, and is one of several accepted notations for uncertainty in the scientific community. You understood this correctly, and yes, I too was slightly confused the first time I encountered it. I'm undoing your change to keep this page consistent with common practice. Regarding the actual numbers, the ones on this page should match the most recent "universal" (containing all available isotope data at the time) source, {{NUBASE2016}}. In that case, List of radioactive nuclides by half-life would be outdated, and it turns out that is quite incomplete as well. Should more recent data be available, though, I'll take a look and update if necessary. ComplexRational (talk) 16:09, 3 September 2021 (UTC)
I just checked hydrogen-7 because of the suspiciously large change, and the currently cited source actually says 2.3 x 10-14 ns, which is equal to 23 ys. So the large edit of many numeric values got this one wrong, and H-7 is still the shortest-lived isotope known. I have now changed the value back in this article. Dirac66 (talk) 01:53, 4 September 2021 (UTC)
EDIT: @Dirac66: Original editor here. The reason I edited the values of the short-lived hydrogen isotopes to the previous ones was to align it with NUBASE2020, which (at the time of writing this) is the most recent update (you can find the original paper here and a link to download the table here). In NUBASE2020, the half-lives of the unstable hydrogen isotopes are given as such:
* hydrogen-4 has a half-life of 139(10) ys
* hydrogen-5 has a half-life of 86(6) ys
* hydrogen-6 has a half-life of 294(67) ys
* hydrogen-7 has a half-life of 652(558) ys
Hope this helps explain why I made the numerical changes! :) MeasureWell (talk) 07:33, 16 September 2021 (UTC)
At present the table (with the source link in the wrong column) says 652 ys for H-7 and the text about H-7 says 23 ys (without source).--BIL (talk) 20:20, 17 September 2021 (UTC)
The 23 ys value is not without a source; it is sourced to periodictable.com although I will admit that that website does not look too authoritative. However the Nubase values are not sourced to primary research articles either, so we don't really know which is correct. Perhaps we should give both values with question marks, and wait for someone more familiar with the original papers to sort out the confusion. Dirac66 (talk) 02:31, 18 September 2021 (UTC)
@BIL: @Dirac66: If you read my previous comment (as well as the sources that I linked), you'll see that I got the value for the half-life of hydrogen-7 (the one that, at the time of writing, is currently in the table) from NUBASE2020. If you go to the table displaying the NUBASE2020 values, you will find an abbreviation for the original reference in the 7th column. After a bit of digging thanks to this website, I've found the original paper for hydrogen-7 here (yes, I know it's locked behind a paywall, but that's nothing Sci-Hub can't fix), although it doesn't explicitly state the half-life of hydrogen-7, as far as I can tell. —MeasureWell (talk) 01:26, 19 September 2021 (UTC)
@MeasureWell: @BIL: I have found NUBASE2003 which was the real source for the old 23 ys value. It is no longer on the Internet but I found an archived version cited in the article Radioactive decay), which is available at https://web.archive.org/web/20110720233206/http://amdc.in2p3.fr/nubase/Nubase2003.pdf The half-life for H-7 is on p.27. So since the value 23 ys has been replaced by 652 ys in the currently posted NUBASE2020, I will agree that we should now quote the value 652 ys, in this article and in List of radioactive nuclides by half-life. Dirac66 (talk) 21:08, 22 September 2021 (UTC)
As for the 2008 article by Caamaño et al., I accessed it through my university but couldn't find the half-life of H-7, and then I noticed your comment that you had not found it either. So let's say that it is a paper about H-7 (and H-6) but not the source of the half-life value, and we still do not have the primary source of this value. Still, Nubase is certainly a "usually reliable source" for Wikipedia, so we can go ahead and quote 652 ys. The 23 ys is clearly an obsolete value from a previous version of NUBASE which has been replaced by its editors. Dirac66 (talk) 21:17, 22 September 2021 (UTC)
@Dirac66: Thanks mate! :) —MeasureWell (talk) 05:07, 23 September 2021 (UTC)

New mass values and uncertainties

@MeasureWell: I see that you have added more figures to the masses and their uncertainties for the short-lived isotopes. Two problems: 1. It is not clear what is the source for the values with so many figures. I looked at both Weng et al. and Kondev et al. and couldn't find the values with all these figures. Could you specify the pages with the data? 2. The table with List of isotopes now has some uncertainties written as ± and others in parentheses, which is very confusing. I realize that the values with ± and the ones in ( ) come from different sources, but it is good practice in each article to choose one notation and stick with it even if it does not match the notation of all the sources. Dirac66 (talk) 01:11, 26 September 2021 (UTC)

@Dirac66: Hi mate. I got the AME2020 II values for the atomic masses from the file "mass_1.mas20" (it displays the full uncertainties of the mass values) which you can find here. Scroll down a little bit, and you will also find the NUBASE2020 files. If you have a look at the website, it says, below all of the files listed:
"Any work that will use these files should make reference to the original papers listed above, and not to the electronic files."
As for the inconsistent notation, that's no problem at all - feel free to edit it so that it's consistent. In the actual file, the uncertainties are listed in a separate column in full - the parentheses notation was just me. :) —MeasureWell (talk) 01:50, 26 September 2021 (UTC)
Also, in case you were wondering why I added more figures to the masses and their uncertainties, it was the consensus from a conversation I had at the Teahouse that you can find here. — MeasureWell (talk) 01:52, 26 September 2021 (UTC)
The Teahouse content seems to be archived every few days. I have found a more direct link to your archived conversation here Dirac66 (talk) 19:59, 30 September 2021 (UTC)
Out of curiosity, why change the rounding at all, given the source? I read "more than 2 significant figures, ... with two significant figures in the uncertainty (which, as far as I can tell, is the most common practice)". Whose common practice is this, like: in-wiki or in RL? -DePiep (talk) 20:29, 30 September 2021 (UTC)
@DePiep: Sorry for the late reply! For clarification: when I wrote the "two significant figures in the uncertainty (which, as far as I can tell, is the most common practice)", I had RL in mind. For example, the GUM, which is published by the BIPM and is the standard for expressing uncertainty, (paragraph? section?) 7.2.6 reads:
"The numerical values of the estimate y and its standard uncertainty uc(y) or expanded uncertainty U should not be given with an excessive number of digits. It usually suffices to quote uc(y) and U [as well as the standard uncertainties u(xi) of the input estimates xi] to at most two significant digits, although in some cases it may be necessary to retain additional digits to avoid round-off errors in subsequent calculations."
The above is also normally what I do if I'm evaluating the uncertainty of a quantity using, say, the NIST Uncertainty Machine (for context: I like to calculate/find the values of certain measured quantities for no good reason whatsoever in my free time). However, I wasn't sure whether this was the case or not on Wikipedia, which is why I asked the question at the Teahouse in the first place. Like I mentioned earlier, the consensus from that discussion was that I should display the uncertainties out in full (i.e. to all digits given in the table; you can find the link to that in my previous message), because people might otherwise think that the values rounded off so that they display two significant digits in their uncertainties are the "true values", when in reality, they are not. Hope this helps! :)
(Also, I will go and fix up the uncertainty notation so that it's consistent - I just haven't gotten around to it yet.) — MeasureWell (talk) 06:24, 3 October 2021 (UTC)

Uncertainties and the number of digits given for the relative atomic masses

@ComplexRational: I noticed that you changed the values in the table so that their uncertainties are displayed using parentheses. Please read the above section which shows why I originally displayed the AME2020 and NUBASE values with the ± notation, as well as a link to access the source. :-)

— MeasureWell (talk) 07:13, 29 December 2021 (UTC)

@MeasureWell: Thanks for the ping. I read through the above section and the archived Teahouse thread. I am aware of the practice of (generally) quoting at most two significant figures of error, though the values I found in {{AME2020 II}} are not the same ones you originally quoted. The uncertainties of the values I read through typically are given with at most two significant figures, except for systematic estimates given in lieu of a precisely measured value (e.g., for hydrogen-7). For instance, hydrogen-4 has a mass of 4.026430±0.000110 u (p. 030003–6), which can be nicely shortened to 4.02643(11) – two significant figures of uncertainty, as desired. In these cases, using ± notation doesn't format so nicely (smaller text in a wider column), and I'm not following the reasoning in the Teahouse thread, since it wouldn't seem to apply when the value or uncertainty don't need to be truncated.
It seems to me that you converted energy (in keV; from {{NUBASE2020}}) to mass (in u), which would explain why there were so many extra digits? In that case, general practice is to use exact conversion factors and keep the same number of significant figures as your original quantity (since that is probably the least precise value in the calculation). ComplexRational (talk) 15:25, 29 December 2021 (UTC)
Aha. The values of the masses (and uncertainties) differ between the electronic file [8] and the PDF {{AME2020 II}}. I was previously unaware of the electronic file, so I used the PDF and the fewer digits it gives (already rounded?). Since, after all, it is bad practice to quote (for instance) 10 digits of which 5 are uncertain, I'm inclined to stick to the PDF values, which make more sense and are more comfortably representable in the table.
Maybe I should raise this issue of incongruent values on another discussion page? And it's rather confusing whether to use rounded values and adhere to proper numerical representation rules, or use exact values (which IMO seem dubious in a few cases, but I'll need to consult other sources) with 5+ digits of uncertainty in some cases. ComplexRational (talk) 16:45, 29 December 2021 (UTC)
@ComplexRational: OK, right, good idea. As far as I can tell, Wikipedia doesn't actually have any "official" policy regarding the number of significant digits that should be shown in uncertainties (I checked the related Wikipedia MOS page yesterday, and there wasn't anything; why else would we be having this conversation then? :-) ), so, provided that you have the authority, it would probably also be a good idea to add this to the Wikipedia Manual of Style, so that we don't need to have this discussion again in the future.
Thanks for the relatively quick response, as well as explaining the reasoning behind your edit :) Please let me know what the final consensus is on this (potentially somewhat controversial) subject – in the meantime, I guess I'll avoid editing any of the "Isotopes" articles for now.
—MeasureWell (talk) 19:49, 29 December 2021 (UTC)
@MeasureWell: I also couldn't find any clear solution in MOS. On the talk page, I found this thread, which basically suggests that on WP the number of digits is left to the editor's judgement, while acknowledging that excess precision is widespread. On the other hand, WP's own article on significant digits and some various sources state (or at least imply) to use only 1 or 2 significant digits of uncertainty – indeed this is also what I was taught in data analysis.
Regarding the isotope data, I also noticed in the NUBASE files that the values of mass excess are quoted to about 9 significant figures total (unrounded; with 2-3 digits of uncertainty), so I would think to not go above that number when quoting masses. Using the rounded files (as in the PDF) would be sufficient without giving excess precision (except for the few nuclides whose masses are extremely well-known).
Rather than boldly edit the MOS, I'd rather open another discussion thread on the talk page and gauge others' opinions if it won't be redundant to the already-present thread. Do you think this is the best course of action? (I can also pause updating the articles in the meantime.) ComplexRational (talk) 23:13, 29 December 2021 (UTC)
@ComplexRational: I mean...the thing is, I'm still quite new to Wikipedia, so I'm not really in the greatest position to judge :) However, that does seem like the best course of action, so yeah, go ahead.
Also, here's another note relating to my experience with sig figs in uncertainties – from all the scientific papers that I have read so far (excluding AME2020 and NUBASE2020), uncertainty-wise, all of them have generally used 1 or 2 significant figures for the uncertainties (or at most 3), which conforms with the GUM (Guide to the Expression of Uncertainty in Measurement; published by the BIPM and ISO). In other words: you're correct :) However, the document (as well as a supplement to the GUM) also states that additional digits should sometimes be kept to avoid round-off errors. For the (probably very few) people who visit these pages that need the lowest uncertainties possible for their own purposes, is it also possible to add the link to the electronic files somewhere on the page (provided that it doesn't violate the MOS or anything?)
— MeasureWell (talk) 23:48, 29 December 2021 (UTC)
MOS:UNCERTAINTY is clear about rounding: "explicit uncertainty information (such as a margin of error) is available and appropriate for inclusion, ...". This applies here. WP has no business introducing rounding by own, editoring initiative. For this, invoking BIPM (as MW did above) is also part an editorial action (apart from the fact that BIPM/GUM is about how to roundpresent rounding by scientific reasons & math, not editorial "can be nicely shortened to .." [MW @16:45]). If rounding were applicable in RL usage, and in some form, it is up to the Reader (say a scientist) to handle the rounding—at their own responsibility.
Sure a diff between pdf and electronic file, as CR found (good action!), is troublesome. Didn't this edit by MW already solve the issue, per the Holy Source? (i.e., use pdf).
All in all I see no reason or right to round the sourced values. It is not trerivial, it is changing sourced values. There is no RL consensus on how to handle these values differently.(FYI and by interesting example, CIAAW themselves publishes "rounded" values together with their long or compound range values: see Standard atomic weight § List of atomic weights). -DePiep (talk) 07:15, 30 December 2021 (UTC)
Good to know; I was unaware of the other thread. PDF it is then – as quoted, not introducing additional rounding. ComplexRational (talk) 17:36, 30 December 2021 (UTC)
@DePiep: So, just to double-check: use the PDF for all AME2020 II and NUBASE2020 values? Thanks :)
— MeasureWell (talk) 03:11, 31 December 2021 (UTC)
I myself did not saw any diff, and I did not check the pdf for that statement. I was just quoting CR. (I'd look it up before making edits, but time limits here ;-).
A pity though because if I wanted to update automatically by bot or update the isotopes on Wikidata I'd prefer using the file. -DePiep (talk) 08:03, 31 December 2021 (UTC)
Some of the files could conceivably still be used for semi-automation – as their contents are exactly reflected in the PDFs. Indeed, the PDFs are better to use and cite. ComplexRational (talk) 15:48, 31 December 2021 (UTC)
@DePiep: @ComplexRational: I've just looked through the electronic files and the original paper, and I think I've actually found where the authors derived the atomic mass values that are used in the PDF – it's the "massround.mas20" file which you can find here.
By the way guys, sorry for dragging out this discussion for far too long. While I am indeed a big sucker for highly accurate values (I think we all are; that's why I changed the values in the first place), I do also agree that the 5- or 6-digit uncertainties are also very unwieldy and don't look good in the tables. Since you two seem to be far more experienced editors than I am, I'll let you two come to a consensus. Also, Happy New Year :)
EDIT: When you come to a consensus, please ping me. Thanks :) — MeasureWell (talk) 00:58, 1 January 2022 (UTC)

Decay modes of isotopes

I was looking through NUBASE2020 and checking the "Spin and parity" column (which was completely correct :D) and the "Decay mode" column in the table on the main article, and I found that the decay modes given for 6
H
 and 7
H
 are incorrect. Furthermore, in the original PDF and the electronic files, there is a question mark next to the decay modes (separated by a space), which is clarified in the paper as meaning that the decay mode is

"energetically allowed, but not experimentally observed."

Given that this definitely seems somewhat important, should we correct the decay modes, add the "?" notation used in NUBASE2020, and then clarify it in the table notes or something? I'll continue to double-check and edit the atomic mass values in the other isotopes articles and make sure that they're presented with the values in the original paper.

Also, here's a link to the NUBASE2020 paper [9] and the electronic files [10].

Cheers — MeasureWell (talk) 05:25, 20 January 2022 (UTC)

I have now corrected the decay modes as per Nubase, and also changed the daughter isotopes accordingly. I agree that the "?" symbol should be explained, and I would add after the footnote text "Modes of decay n neutron" the words "? Energetically allowed, but not experimentally observed." as per Nubase. However I cannot find the footnote text to edit. Dirac66 (talk) 16:47, 10 February 2022 (UTC)
Is it one of the Template:Isotopes table § Table footnotes that needs an edit? One can always add an individual <ref group="n">- footnote. -DePiep (talk) 13:55, 11 February 2022 (UTC)
What I think needs an edit is the source code for the section List of isotopes which produces note 2 after the table: "Modes of decay n: Neutron emission". I would like to add what "n ?" means as per Nubase, as I have indicated above. Dirac66 (talk) 21:08, 11 February 2022 (UTC)
@Dirac66: @DePiep: Thanks for the reply, and sorry for the late response! By the way, I also asked the same question on the WikiProject Physics talk page here. Regarding the NUBASE notation, I also mentioned in the other talk page that NUBASE also uses the notation "α=?" (α used as an example) to show that "α-decay is observed [in this isotope], but its intensity is not experimentally known" for some other non-hydrogen isotopes, so while you're at it, it would also be great to add a footnote explaining this notation as well.
As for DePiep's question, the notation in question does actually pop up for several different isotopes in NUBASE2020, so (in my opinion) it would be more worthwhile to add it to the template, so that it can be easily added to the isotope tables (rather than having to manually add the same footnote to every single table on the "Isotopes" pages). Thanks for getting onto this! :)
MeasureWell (talk) 03:02, 12 February 2022 (UTC)
In principle I agree that it would be better to add the explanatory note to the template, rather than to the article on the isotopes of each element. However I tried and failed to find and modify the source code for the template, so for now I have added a note under the list of isotopes of hydrogen. If someone can figure out how to place a version on the template instead, then I will have no objection. Dirac66 (talk) 22:38, 12 February 2022 (UTC)
@Dirac66: Late reply, but looking at the edit history of that template, it looks like DePiep is the proud creator of Template:Isotopes table. Perhaps you should consider discussing these suggestions with them?
—MeasureWell (talk) 04:56, 13 February 2022 (UTC)
@MeasureWell and Dirac66: Indeed, I planned to dive into this, and add a default footnote option to Template:Isotopes table § Table footnotes. Unfortunately, also for RL actions, I cannot project or promis a timescale for introduction. (Meanwhile, when one encouters such a need, maybe add comment like <!-- n? --> in the Big Table appropriate cells? We can sweep & apply those later on). -DePiep (talk) 16:29, 13 February 2022 (UTC)
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