Talk:Extinct radionuclide

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... [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]