Talk:Extinct radionuclide: Difference between revisions

Content deleted Content added

Inline

Revision as of 17:18, 12 January 2018

Physics Start‑class Low‑importance

	Physics portal This article is within the scope of WikiProject Physics, a collaborative effort to improve the coverage of Physics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.PhysicsWikipedia:WikiProject PhysicsTemplate:WikiProject Physicsphysics
Start	This article has been rated as Start-class on Wikipedia's content assessment scale.
Low	This article has been rated as Low-importance on the project's importance scale.

... [B]eryllium-10 [is] produced by cosmic ray spallation on dust in the upper atmosphere.

I'm not sure this is entirely accurate. What element acts as the parent for this spallation? If it is something between carbon and oxygen, it is possible that some of the spallation actually uses a gas as the parent and not dust. -- B.D.Mills (T, C) 02:59, 12 May 2008 (UTC)[reply]

So... how do they know about these? They supposedly left behind their daughter elements but surely there needs to be more indication.

No, that is usually enough, because the daughters have different chemistries from their parents. If you see a lot of thallium in a place where there should be more lead and very little thallium, one immediately suspects ²⁰⁵Pb to have been there; if one then analyses the thallium and notices that there is a great deal too much ²⁰⁵Tl (the electron-capture daughter of ²⁰⁵Pb) and very little ²⁰³Tl (the other stable thallium isotope), there really is no other good explanation. That's also how extinct ²⁴⁷Cm was found, because curium and uranium have vastly different chemistries. (Mind you, ²³⁵U might be considered to be "almost" an extinct radionuclide too; it and ⁴⁰K are the two primordials with half-lives in the right time range that they have been severely depleted, but they're not reduced to mere traces yet as ²⁴⁴Pu would have been.) Double sharp (talk) 04:33, 14 May 2017 (UTC)[reply]

needs to be more specific

An extinct radionuclide is one that scientists believe was formed by primordial processes, such as stellar nucleogenesis in the supernova(s) that contributed radioisotopes to the early solar system, about 4.6 billion years ago.

Doesn't that also describe stable nuclides? —Tamfang (talk) 04:12, 8 April 2014 (UTC)[reply]

No, because a stable nuclide is not a radionuclide. Dirac66 (talk) 18:37, 8 April 2014 (UTC)[reply]

Dubious parent-daughter relationships

The table in the article as currently written has some problematic entries for "daughter" products. For example, it lists 150Sm as the daughter of 154Dy, however, the page on dysprosium isotopes lists 150Gd as the primary daughter. 150Gd (also in the table) in turn decays to 146Sm via alpha decay, and only rarely would decay by β⁺β⁺ to 150Sm. There are numerous entries in the table where the daughter could not be the immediate daughter, and the listing of some isotopes as stable implies that the ultimate stable daughter is not being listed. ArkianNWM (talk) 17:18, 12 January 2018 (UTC)[reply]

@@ Line 14: / Line 14: @@
 ::No, because a stable nuclide is not a ''radio''nuclide. [[User:Dirac66|Dirac66]] ([[User talk:Dirac66|talk]]) 18:37, 8 April 2014 (UTC)
+== Dubious parent-daughter relationships ==
+The table in the article as currently written has some problematic entries for "daughter" products. For example, it lists 150Sm as the daughter of 154Dy, however, the page on dysprosium isotopes lists 150Gd as the primary daughter. 150Gd (also in the table) in turn decays to 146Sm via alpha decay, and only rarely would decay by β<sup>+</sup>β<sup>+</sup> to 150Sm. There are numerous entries in the table where the daughter could not be the immediate daughter, and the listing of some isotopes as stable implies that the ultimate stable daughter is not being listed. [[User:ArkianNWM|ArkianNWM]] ([[User talk:ArkianNWM|talk]]) 17:18, 12 January 2018 (UTC)