Talk:Decay chain

message: What about the Neptunium series  that describes the decay chain of the transuranic elements?--ragesoss 17:21, 22 January 2006 (UTC)
thread_title: Neptunium series

message: Why is the half-life of Thorium-232 written as 1.405·10^6 a, meaning 1.4 million years?  Since this is dramitically less than the age of the planet, shouldn't this be more like 1.405·10^10 a (this is the number claimed in the Thorium article).  Since I'm no nuclear physicist, I'd rather point this out in the discussion before I tamper with the article. Felix Dance 15:52, 14 April 2006 (UTC)
replies: text: Thanks, I've corrected. Samw 19:24, 14 April 2006 (UTC)
thread_title:  Half-life of Thorium-232 

message: It was suggested that Radioactive decay path be deleted and anything salvagable be merged here. I thought I would dump it here so It wouldn't be lost until I get around to adding it here, or you can add it here ;). The only reason I learned this was to understand how scientists date materials and why no reputable scientist believes the earth is only 6000 years old, as opposed to about 4.5 billion years. I think this is important considering the increasing attacks that pure science has come under from religious and political factions lately in America.
*Radioactive decay paths are an integral part in dating materials. By comparing the relative abundance of various elements in a sample one can estimate its age based on the decay path and half lifes of those elements. Analysis of various Uranium containing Zircon crystals (along with other data) puts the  age of the earth at aboout 4.5 billion years. Decay paths are also important in reactor experiments where the elements produced are so short lived that their existence can only be infered by the abundance and type of their decay products.
* Radioactive decay paths are also important in less than geologic scales such as with Carbon 14 which is used in Radiocarbon dating of organic materials. (yet more testable proof that the earth is more than 6000 years old)
*  Age of the Earth 4.55 Billion (4.55×109) Years
*  Age of the Universe 13.5 Billion (1.34×1010) Years
*  Nuclear Theory : Island of Stability
*  Nuclear Theory : Shell Model
:::Tiki God 14:08, 28 July 2006 (UTC)
thread_title:  Merge from [[Radioactive decay path]] 

message: I know it's a nit, but is it now standard practice in nuclear physics to use the letter 'a' to mean 'years' instead of 'y'? Obviously 'a' comes from the Latin 'annus' ('year'), but a lot of English-speaking Wikipedia readers might not know that.
Karn 23:39, 25 November 2006 (UTC)
replies: text: It's kind of sucky, but after much searching, there does seem to be a real basis for this use in science: see year#Julian year.  Maybe make the "a" a link to this?  — Johan the Ghost seance 22:14, 27 November 2006 (UTC)

text: There are 6 tables in this article, of which only the first uses "y". Again, if you want to change them all in the other five, you go, girl. You can do a find-and-replace, but there are a lot of other "a"s that really should be a's, that you have to put back by hand. Enjoy. SBHarris 21:23, 8 August 2012 (UTC)
thread_title:  a vs y? 

message: The text states "Thus, radon is a naturally occurring radioactive gas, which is a leading cause of cancer in humans."
I'm not an expert in cancer but I think that Rn attributed lung cancer deaths are about 22,000, where all cancer deaths are about 550,000 and radiation attributed cancer is one of the lowest ranked causes.  I think though that lung cancer is the leading death due to cancer, and that Rn attributed lung cancer is number 2 on the list, behind smoking.
Would it more proper to say "Thus, radon is a naturally occurring radioactive gas, which is a leading cause of lung cancer in humans." ?
Jon in Michigan 22:25, 19 June 2007 (UTC)
replies: text: I've clarified with a reference.   Next time, be bold! Samw 00:52, 20 June 2007 (UTC)
thread_title:  Cancer 

message: How does thermal disintegration work? I'm describing a situation where a nucleus is heated to the point where it detonates into a cloud free neucleons. I think this occurs around 1012 Kelvin for helium. Any thoughts? Plasmic Physics (talk) 11:42, 25 October 2008 (UTC)
thread_title:  Thermal Disintegration 

message: This is a really interesting article.  I have some questions that I think this article should address.
First, it seems that the total decay energy and product mass should be constant across all decay paths.  So, for instance,
Bi-212 -> Po-212 -> Pb-208 yields 2252 + 8955 = 11207 KeV
Bi-212 -> Tl-208 -> Pb-208 yields 6208 + 4999 = 11207 Kev
Great.  However, check out these two:
Bi-210 -> Po-210 -> Pb-206 yields 1426 + 5407 = 6833
Bi-210 -> Tl-206 -> Pb-206 yields 5982 + 1533 = 7515
I presume something in the Po-210 branch is carrying off the 682 eV, like a neutrino or somesuch.  This should be noted in the table.
Second question: You have listed the alpha decay of Bi-213, but not the beta decay.  The unlisted beta decay is 97.91% likely, so it should be listed.  I would edit the table, except I'm not sure where you sourced your data.  If I look at http://ie.lbl.gov/toi/nuclide.asp?iZA=830213, I see 5982.6 KeV listed for the alpha decay, instead of the 5870 listed here.  I may be interpreting things differently.
Third question: I came to this article wondering about the relative radioactivity of transuranics versus fission products.  After resolving hopefully minor issues like that above (by, for instance, picking the most likely chain), I think you could list a total decay energy for each element.  So, for instance:
Pu-242: 57005 KeV (using http://ie.lbl.gov/toi/nuclide.asp?iZA=940242)
U-238:  52021
Th-234: 47751
Pa-234: 47478
U-234:  45281
Th-230: 40422
Ra-226: 35652
Rn-222: 30781
Po-218: 25191
Pb-214: 19076
Bi-214: 18052
Po-214: 14780
Pb-210:  6897
Bi-210:  6833
Po-210:  5407
Pb-206: stable
Pu-239: 51645 KeV
U-235:  46401
Th-231: 41723
Pa-231: 41332
Ac-227: 36182
Th-227: 36135
Ra-223: 29988
Rn-219: 24009
Po-215: 17063
Pb-211:  9536
Bi-211:  8169
Tl-207:  1418
Pb-207: stable
I think it's quite interesting that the decay for U-238 is about 1/4 of the energy released by fissioning that same nucleus, and that's what I was looking for when I arrived here.
Iain McClatchie (talk) 09:11, 29 January 2009 (UTC)
thread_title:  Total energy? 

message: The end product of Thorium series id is given as Pb-208. The final product of neptunium series is refined to Tl-205. Pb-208 is also radioactive with a half life (>2E+19 a]) which is just comparable with that of Bi-209 (1.9E+19 a). So the end product should be refined. The radioactivity bad name is given only to bismuth and not to lead-204, lead-208 or even tungsten whose all isotopes are radioactive.Anoop.m (talk) 05:53, 24 January 2010 (UTC)
replies: text: There doesn't seem to be any sources for this information. [IAEA] and [BNL] list Pb-208 as stable. BatesIsBack (talk) 15:24, 15 May 2011 (UTC)
thread_title: Thorium series

message: In the Actinium series section, a diagram is captioned:  This image gives the detailed routes of actinium-237 decay.
However, the article Isotopes_of_actinium does not list actinium with a mass number greater than 236.  Also, the image itself shows no such actinium-237.  Was it supposed to say uranium-235?  Nicknicknickandnick (talk) 07:04, 27 May 2010 (UTC)
replies: text: There are isotopes of elements like actinium that are so rare (have such short half-lives) that they are not worth mentioning in an article about the element. In other words, the article on isotopes of actinium justifiably focuses in the more-common isotopes and omits the rare ones.For example uranium-239 exists, BUT whenever any is produced (usually in a nuclear reactor, or by a collision with a stray neutron), U-239 nearly-immediately emits a beta particle and becomes neptunium-239.Likewise, whenever U-235 absorbs a neutron, it becomes U-236 for about a nanosecond, but that U-236 nucleus breaks "in half" in the process or nuclear fission. Nearly anytime you see a listing for an isotope like Ac-236, then one higher (Ac-237) or one lower (Ac-235) usually exists, but it would be extremely rare. 05:22, 4 June 2010 (UTC)
thread_title:  Confused by a diagram caption 

message: The diagram in the Radium series (also known as Uranium series) section is missing an arrow connecting up from the Po to the At.  Nicknicknickandnick (talk) 07:10, 27 May 2010 (UTC)
replies: text: This has been fixed in the SVG version of the image. BatesIsBack (talk) 15:24, 15 May 2011 (UTC)
thread_title:  Diagram missing an arrow 

message: The diagram in the Neptunium series section has an isotope labelled on the exterior as Actinium 233 but should instead be labelled Actinium 225.  Nicknicknickandnick (talk) 08:07, 11 June 2010 (UTC)
replies: text: This has been fixed in the SVG version of the image. BatesIsBack (talk) 15:24, 15 May 2011 (UTC)
thread_title:  Diagram containing mass number error 

message: I think the half life of Protactinium-233 is the same of  Protactinium-234 in the two diagrams. The one for   Protactinium-234 is wrong.--Stone (talk) 10:34, 25 December 2010 (UTC)
thread_title:  Radium series 

message: WRONG HALF LIFE
The half life of Pa234 is 6.7 h and  NOT 27 d as indicated on the corresponding graph  — Preceding unsigned comment added by 77.49.98.185 (talk) 07:18, 8 June 2012 (UTC)
thread_title:  U238 decay chain  

message: In natural also have a decay chain begins with Gadolinium-152 which undergone triple alpha decay to form stable nuclide Cerium-140 (this nuclide contains 58 protons (semi-magic number) and 82 neutrons (magic number) thus exceptionally stable and can't decay further exempt for spontaneous fission).
Atomic mass He-4 4.002602u, Gd-152 151.919791u, Sm-148 147.914823u, Nd-144 143.910087u, Ce-140 139.905439u
Gd-152 => Sm-148 released 2.2MeV
Sm-148 => Nd-144 released 1.97MeV
Nd-144 => Ce-140 released 1.91MeVCristiano Toàn (talk) 09:06, 4 December 2012 (UTC)
replies: text: Yes, but the problem is that 152Gd, 148Sm, and 144Nd all have half-lives longer than the age of the universe, so every step is a bottleneck in the decay chain and so it happens really slowly. It's not as though the intermediate products would not exist but for a long-lived rate-limiting isotope higher in the chain, which is what happens with the chains from 232Th, 235U, and 238U. Double sharp (talk) 14:32, 3 September 2014 (UTC)
thread_title:  Gadolinium-152 decay chain 

message: Why is the decay product called 'daughter' instead of the gender neutral 'child'? surely atoms do not have a social gender or a vagina. 71.82.220.226 (talk) 17:31, 4 October 2013 (UTC)
replies: text: if this is due to the decay product potentially decaying and giving birth to another 'child' then is the final stable isotope called a son(one who does not directly give birth)?  — Preceding unsigned comment added by 71.82.220.226 (talk) 17:35, 4 October 2013 (UTC)
replies: text: There is not a final stable isotope beyond Nickel-62 and Iron-56 (which is considered nuclear 'ash' not 'son'). Woosley, S.; Janka, T. (2006). "The physics of core collapse supernovae". Nature Physics. 1 (3): 147–154. arXiv:astro-ph/0601261. Bibcode:2005NatPh...1..147W. CiteSeerX 10.1.1.336.2176. doi:10.1038/nphys172 I feel the term 'daughter' adds respect and acknowledgement to the feminine. Atoms do not have vaginas, but they do spawn new, typically more stable, generations. I think identity politics should be kept out of the natural sciences. The atom isn't asking to be called anything in our language. Einstein A, Podolsky B, Rosen N; Podolsky; Rosen (1935). "Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?". Phys. Rev. 47 (10): 777–780. Bibcode:1935PhRv...47..777E. doi:10.1103/PhysRev.47.777 2001:569:BE91:F500:E978:E8DE:434E:19D8 (talk) 20:18, 25 February 2021 (UTC)

text:  Tradition.  Like ships. SkoreKeep (talk) 04:22, 17 February 2014 (UTC)
thread_title:  Gender specific nomenclature, institutionalized sexism 

message: If the half-life of an isotope is 100 million years, then the amount left after 4.5 billion years is 2^-45 of the original amount, or 2.8e-14.  That's 0.000000000000028 of the original, or 0.0000000000028%. SkoreKeep (talk) 00:09, 21 February 2014 (UTC)
thread_title: Percentage of remaining decaying isotope 

message: This article lacks any inline citations and reads like original work.
173.243.179.223 (talk) 14:34, 25 February 2017 (UTC)
replies: text: (Moved from the top of the talk page.) I agree that the lack of citations is a problem, but it is most definitely not original research: all of these decay chains were known from the early history of the discovery of radioactivity, even if of course some of the isotopes in them remained to be discovered later (for example, the isotope with 227Ac as its daughter was looked for by many until it was finally found by Hahn and Meitner in 1918). It is very easy to find sources listing these decay chains online simply by searching those names; they are all mentioned in Greenwood and Earnshaw (chapter 31 is on the actinides and includes these). Double sharp (talk) 15:49, 25 February 2017 (UTC)
replies: text: Agree.  This data was known before some of the decaying elements were officially discovered and named themselves. SkoreKeep (talk) 21:43, 15 June 2017 (UTC)
thread_title: Original research?

message: I have a set of paper diagrams with the mass number as the y axis and the atomic number as the x axis.  These seem very clear, even if not as pretty as the ones we have.
I was wondering if it would be possible to put all four series on the same diagram using different colours for them.
All the best: Rich Farmbrough, 19:46, 15 June 2017 (UTC)
replies: text: I don't know what is the meaning of the different colors in the four decay chains, or why the uranium chain has hexagons rather than spheres. I suppose that we'd have to see what your combined diagram looks like. Would it be possible for a person to print out the combined diagram and then cut them apart, if that is their preference. Easier than printing four diagrams and pasting them together? TomS TDotO (talk) 20:33, 15 June 2017 (UTC)
replies: text: It's apparent that the diagrams were done by at least two different people.  The color codes seem to be indicating classes of elements (halogens, etc) but they aren't consistent. By all means bring in a different set of diagrams; if you need help I'm sure there are artistic resources to make correct diagrams as pretty as anyone could desire them.  As for combining them, I'd personally rather see each diagram matched with its text as it is now; I don't see a point in being parsimonious with page space, since there seems to be a lot available.  Also the vertical arrangement of the existing charts works with that.  Not being a chemist I'm not into the color scheme being used; there has to be a better use of the information space, I think. My 2 cents.  SkoreKeep (talk) 21:39, 15 June 2017 (UTC)
thread_title: Yet  more diagrams

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thread_title:  External links modified 

message: Alone of the four tables the Radium table is called by a macro "uranium/radium chain" and woe is me, I don't know how (more likely where) to edit such a thing.  Perhaps all I need is a spot of assistance here?  Is there any need to have broken out the table into a separate file for just this one?  I'm just an engineer; I don't know any better.
The reason it needs editing (as far as I would like) is that it is inconsistent with the other tables.  Instead of grouping together different decay modes of a single parent in a single table row, it has separated them out into separate table rows.  Yeah, I know, consistency is the hobgoblin..., but is there some reason it should be that way?  I also notice that at least one low-probability chain is just dropped: the Pa-234 result of decay from Pa-234m.  My presumption is that if you mention it, then it's best to follow through.
One last change I'd make is getting rid of the Subtotal MeV column. The total is mentioned in the text, and adding it up as we go seems oddly unuseful.  I'd also combine the decay mode and probability in a single column - consistency again. The table is a lot wider than the others because of these. SkoreKeep (talk) 23:48, 29 June 2019 (UTC)
replies: text: The table is at  – I suspect because our article on uranium-238 uses it too. BTW, 234Pa (UZ) is there, but it immediately beta decays to 234U and rejoins the main chain. I agree with what you say; and I also think that if we want consistency, we should also start the chain off with 250Cf, 246Cm, and 242Pu, since we start the other chains off with 249Cf, 251Cf, and 252Cf. Double sharp (talk) 03:09, 30 June 2019 (UTC)
replies: text: After considering it a bit, I've decided to create a new table in the decay chain article so that the source code matches with that of the other three tables, as well as adjusting the columns and rows as I discussed.  It appears that each of the tables (or at least three of them) were once bound as the radium series table is now, but were eventually made distinct. Oh, and thanks for the information, Double sharp, I learn something new every day.   SkoreKeep (talk) 06:12, 30 June 2019 (UTC)

text: Did it.  Please cross-check for any errors.  Will look up values for additional rows at top of table tomorrow. SkoreKeep (talk) 08:11, 30 June 2019 (UTC)
replies: text: I added three more rows at the top for 250Cf, 246Cm, and 242Pu, with data from Theodore Gray's website. Double sharp (talk) 15:51, 30 June 2019 (UTC)
thread_title: Radium/Uranium chain

message: I'm no expert, is there a reason why gamma emissions aren't mentioned anywhere? Is there any material on how much gamma radiation is emitted at any given decay step in a chain?  190.100.175.35 (talk) 07:34, 4 August 2020 (UTC)
replies: text: Gamma emissions are not mentioned anywhere because they do not result in the conversion of one nuclide to a different nuclide, only the release of excitation energy. This contrasts with alpha and beta decay, which respectively convert (Z, N) into (Z − 2, N − 2) or (Z + 1, N − 1). As such, there is no change to reflect in the table. ComplexRational (talk) 15:43, 4 August 2020 (UTC)
replies: text: Yes, I understand that, but why is that a valid reason not to include them? It would seem to me gamma emissions are a large part of the reaction and can have serious consequences, why is that not enough for their inclusion? 190.100.175.35 (talk) 16:05, 4 August 2020 (UTC)

text: If this has been discussed and sufficiently answered before I would gladly be pointed to said discussion. No desire to beat a dead horse. But I would like to know if there's a way for me to find out how much gamma, if any, is emitted at each step. 190.100.175.35 (talk) 16:10, 4 August 2020 (UTC)
thread_title:  gamma? 

message: 210-Po is written as decaying via alpha decay into 206-Tl instead of 206-Pb, but this would require an alpha particle of 3 protons, would it not!  I wonder if there are other such errors in the data.
--RProgrammer (talk) 23:52, 23 October 2020 (UTC)
replies: text: You're right, it's an error. Corrected; thank you! Double sharp (talk) 23:54, 23 October 2020 (UTC)
thread_title:  Error in data 

message: https://en.wikipedia.org/wiki/Nuclide says, 
"Since isotope is the older term, it is better known than nuclide, and is still occasionally used in contexts in which nuclide might be more appropriate, such as nuclear technology and nuclear medicine." and 
"Although the words nuclide and isotope are often used interchangeably, being isotopes is actually only one relation between nuclides. The following table names some other relations." 
and 
"A set of nuclides with equal proton number (atomic number), i.e., of the same chemical element but different neutron numbers, are called isotopes of the element. Particular nuclides are still often loosely called "isotopes", but the term "nuclide" is the correct one in general (i.e., when Z is not fixed). In similar manner, a set of nuclides with equal mass number A, but different atomic number, are called isobars (isobar = equal in weight), and isotones are nuclides of equal neutron number but different proton numbers. Likewise, nuclides with the same neutron excess (N − Z) are called isodiaphers. The name isotone was derived from the name isotope to emphasize that in the first group of nuclides it is the number of neutrons (n) that is constant, whereas in the second the number of protons (p)." Polar Apposite (talk) 16:54, 14 July 2023 (UTC)
thread_title:  Would "nuclide" be more appropriate than "isotope" in this article? 

message: It's very hard to see that the arrows indicating alpha decay of francium-223, beta decay of polonium-215, and beta decay of bismuth-211 are not solid but dotted, in the diagram of the actinium series. This seems to be because the arrows in the diagram are rather narrow, unlike those in the diagram of the uranium series, which are wide, and thus allow the dotted lines to be easily distinguished from the solid ones. It is also hard to see that there are two kinds of dotting, big and small, or, if you prefer, dotted and dashed. So I think it would be great if someone who knows how to edit the actinium series diagram would thicken the arrows. Polar Apposite (talk) 14:48, 20 July 2023 (UTC)
thread_title:  Dottedness of arrows too hard to see in the actinium series diagram. 

message: I don't see why there are two both dotted and dashed arrows in the actinium series diagram. It seems to me that the dashed arrow could be replaced with a dotted one. Also, the dashed arrow representing the beta decay of bismuth-211 is very unclear, and looks like it could me a misprint. Polar Apposite (talk) 18:48, 20 July 2023 (UTC)
thread_title:  Need for both dotted and dashed arrows.