Talk:Decay chain

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)

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)

There is not a final stable isotope beyond Nickel-62 and Iron-56 (which is considered nuclear 'ash' not 'son'). ^[1] 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. ^[2] 2001:569:BE91:F500:E978:E8DE:434E:19D8 (talk) 20:18, 25 February 2021 (UTC)

I honestly never thought about this! (But if you feel that the term is sexist, you can use "decay product", which is probably fine.) As for your final question, in general after granddaughters this terminology stops actually getting used, and the final product seems to be mostly called just that: "final (decay) product". Your rationale is probably the reason, though. (These final products are theoretically predicted to decay anyway, even though the decay hasn't been seen yet, so I suppose "son" would be overly restrictive here. ) Double sharp (talk) 04:34, 5 October 2013 (UTC)

Tradition. Like ships. SkoreKeep (talk) 04:22, 17 February 2014 (UTC)

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)

I am repeatedly reverting an edit by User:SkoreKeep. Here is the rationale.

Along a family of isobars, there is generally an optimal n/p ratio that yields the lowest energy and thus the higher stability. The nuclide energy tends to increase as we move further from this optimum. Since alpha decay products tend to be born with a higher than optimum n/p ratio, some of them beta-decay into nuclides of lower n/p ratio and hence lower energy. This is the point of the beta-decay: to decrease energy by lowering the n/p ratio. It's not about "being more tolerant" to a high n/p ratio.

I tried to make sense of the sentence anyway. What would it mean to say "nuclide A is more tolerant of a high n/p ratio than nuclide B"? If nuclide A has an n/p ratio that is higher or equal than that of nuclide B, and yet A is more stable than B, then A is indeed more tolerant of a high n/p ratio. However, is the more stable of these nuclides has a lower n/p ratio, then it makes no sense to say it is more tolerant of a high n/p ratio. — Edgar.bonet (talk) 09:43, 26 February 2014 (UTC)

OK, I'll take a look at it again tomorrow, and see what I've done wrong, and try to get it correct, and a little less loosely worded.

What exactly does it mean to have "repeatedly reverted" my edit? As far as I can see, it makes sense to revert it if it is egregiously wrong (which it sounds like it may be), but you didn't revert at all, just changed the wording. SkoreKeep (talk) 11:15, 26 February 2014 (UTC)

I mean I changed the wording twice, both times in more or less the same way ("more tolerant of a high n/p ratio" → "with a lower n/p ratio"). I cannot say it's egregiously wrong: for me it's more like a confusing wording I cannot make proper sense of. — Edgar.bonet (talk) 08:44, 28 February 2014 (UTC)

This article lacks any inline citations and reads like original work. 173.243.179.223 (talk) 14:34, 25 February 2017 (UTC)

(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)

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)

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).

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)

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)

This is the sort of thing I had in mind except with transposed axis: of course someone has already thought of it. I was also considering line thickness as 1/(log₁₀₀₀ half-life). All the best: Rich Farmbrough, 12:03, 19 June 2017 (UTC).

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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)

The table is at {{Radium series/table}} – 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)

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)

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)

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)

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)

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)

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)

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)

This is related to the last question. Its just curiosity, but isn't something I can answer from the article.

Suppose you were to create a museum of the elements, with a sample of each (practical) element in a display case, and were able to synthesize kg quantities of any long-lived isotope you liked. Alpha decay would be acceptable because the glass of t:{he case would be enough to block the radiation. Which radioactive elements would be safe to display to the public, assuming we ventilated to eliminate radon?

For example, Tc-97 and Tc-98 both have 4My half-lives and decay to stable isotopes, so there are no radioactive products to worry about. But one decays by beta or gamma-emission, both of which would irradiate the audience, and the other by electron-capture, which also produces gamma rays. Unless the amount of radiation from a kg chunk of Tc was not much about background, Tc would not be a safe element to display.

Pu-238 famously can power a spacecraft, but a piece of paper will block its radiation. It would be really cool to have a red-hot kg of Pu-238 in a display case, where people could feel the heat radiating through the glass (and heating the glass). But what of gamma radiation from its decay products? What dosage would we be looking at, and how much would that increase after leaving it on display for a decade or two? Pu-244 wouldn't be as spectacular, but would presumably be safer. Would it be possible to have a kg of the most stable isotope of thorium, uranium or plutonium on display in a glass case, since they all alpha-decay? Would any others be possible? — kwami (talk) 09:31, 15 September 2020 (UTC)

@Kwamikagami: Interesting question. The difficulty for most of the more radioactive elements is really self-heating from the radioactive decay: already a gram of pure radium is problematic. So I think you might not be able to get that many radioactive elements displayed in significant quantities even if we didn't consider the safety. Double sharp (talk) 10:06, 15 September 2020 (UTC)

I wasn't sure radium would be possible. Thought I'd see if the more stable isotopes would be possible first.

Yes, the Pu-238 fuel pellets in spacecraft are the oxide, but Pu-244 has a much much longer half life than radium. But even if pure metal Pu-244 reached its melting point of 640C, there's no reason the kg on display couldn't be liquid.

Pu-242 only generates 0.1 W/kg, and 244 should be less, but our article doesn't include it in the table, so perhaps it's too difficult to synthesize. — kwami (talk) 10:25, 15 September 2020 (UTC)

@Kwamikagami: That's right, Pu-244 is hard to synthesise because Pu-243 has a too short half-life, so you cannot get to it by slow neutron captures. It can be made via nuclear explosion, or by going up to Cm-248 by slow neutron capture and waiting for the alpha decay, but doing it the latter way means lower yield. My worry was not just about liquefying the sample, but also where it's contained (because that's surely going to heat up).

Most stable isotope half-lives go basically Bi (1E19 y) >> Th, U (1E10 y) > Pu (1E8 y) > Cm, Tc (1E7 y) > Np (1E6 y) > Pa (1E5 y) > Am (1E4 y) > Ra, Bk, Cf (1E3 y) > Po (1E2 y) > Ac, Pm (1E1 y) > Es, Fm (1E0 y), rounding to the nearest power of ten logarithmically, FWIW. If Pu-242 is OK, then it seems to me that heating concerns should allow everything up to Np on that list. The worry would then be from gamma, but I suppose you could display it with leaded glass. But I am certainly no expert on radioactive safety, just an interested amateur who has never even seen uranium in person. XD Double sharp (talk) 11:16, 15 September 2020 (UTC)

Leaded glass wouldn't be enough, would it? The electrons would hit the glass and I would think the gamma rays from their deceleration would go right through. If leaded glass is enough, then I would think most long-halflife isotopes would be displayable. — kwami (talk) 11:37, 15 September 2020 (UTC)

Any mass attenuates gamma rays. Dry air will attenuate them at the rate of 1/2 their intensity for 200 meters (600 feet), or by a factor of about 256 per kilometer, about 1000 per mile. That is why people could watch an atomic test at six miles range with no radiation effects. So for leaded glass (or unleaded glass or water or anything else), it's just a question of getting enough in place between you and the source to reduce the gamma rays to acceptable levels. The worst possible source of radiation, fresh spent fuel rods, can be stored in a water pool with 2 meters of water between the rods and people working in a shirt-sleave environment.

Gamma rays do not decelerate - they are a form of EM radiation, like light, and travel at the speed of light in the medium they are in always. SkoreKeep (talk) 16:50, 15 September 2020 (UTC)

I meant gamma radiation from when the electrons decelerate. (Or from traveling faster than the speed of light in their medium.) That's why something that will absorb electrons may not be enough shielding for beta radiation.

Is the factor of 256 per km in addition to the square-distance attenuation of an omnidirectional source?

Still, I'm curious about how much shielding would be needed for the various long-lived isotopes. — kwami (talk) 23:59, 15 September 2020 (UTC)

No, the inverse-square effect is not part of the shielding effect; it is in addition to it. The factor of 256 per km does not include it. I don't know what bremmstrahling will add to the gamma radiation from decay, but it will still have to pass through the glass and likewise be attenuated. SkoreKeep (talk) 14:15, 16 September 2020 (UTC)

So I guess my question is, where do I go to find out how much glass (or what kind of glass) is required to shield a strong beta emitter, so it can be safely observed? — kwami (talk) 23:10, 17 September 2020 (UTC)

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)

@RProgrammer: You're right, it's an error. Corrected; thank you! Double sharp (talk) 23:54, 23 October 2020 (UTC)

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)

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)

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)

I have completed revision of the entire decay chains - in the section I have titled "Heavy nuclei (actinide) decay chains" - in this I operated under the assumption the the individual sections on the four decay chains are basically data, and can (and should) be linked to directly for that purpose, while the introductory sections are where any general information belongs. I have not attempted to rewrite these.

I note only two things:

- The note at the start about omitting 'very minor' branches would require the deletion of Hg-206, as the alpha decay of Pb-210 is less than one in a million. I have not done this; I don't object to it myself, but Hg-206 is elsewhere listed as naturally occurring.

- The historical names for the isotopes are and should be retained. However, the only reference we have for it is on radium G specifically, which seems inappropriate as the entire system is equally important. 73.228.195.198 (talk) 12:38, 15 July 2025 (UTC)

The second problem has been solved by using the source for the historical names taken from Template:Radium series/table - though I have not seen it myself, I have no doubt it contains the information. I do have 'Radiations from Radioactive Substances', which contains all but a few of the names and symbols (and I could easily source those if I had to), so I can be confident in its correctness anyway. 73.228.195.198 (talk) 03:35, 17 July 2025 (UTC)