Talk:Mononuclidic element

Merging with monoisotopic
I'm well aware that one is a strict subset of the other the sets are not equal, but I think it would be more useful to describe them both in one article, because they're so closely related. Any thoughts? —Keenan Pepper 18:07, 11 May 2010 (UTC)


 * As the articles make clear (apparently in vain!), neither is a subset of the other; they are disjoint sets. There are many (19) in common (both mono nuclidic and isotopic), but there are 3 mononuclidics that are not monoisotopic, and 7 monoisotopics that are not mononuclidic. S  B Harris 00:49, 12 May 2010 (UTC)


 * Sorry, I was in a hurry when I wrote this and didn't look too closely at the articles. However, your statement that "they are disjoint sets" is certainly false as well (disjoint sets have no elements in common).
 * Anyway, this isn't all that relevant to the question of whether to merge the articles. Even though they're not the same (and neither is a subset of the other), they're certainly closely related concepts, so I think it would be better to have one article that describes both of them (and explains the difference). —Keenan Pepper 01:49, 12 May 2010 (UTC)


 * Okay, two sets with a big overlap, but neither is a subset of the other. Anyway, the problem is: what do you call an article about two such things? It's the same problem we're having with isotope and nuclide. Nobody likes isotope and nuclide, but the article needed is about the union of the two categories, if you're to describe them all. The only good solution to that is two articles. S  B Harris 05:29, 12 May 2010 (UTC)

Plutonium
Plutonium is also considered to be a mononuclidic elemant due to the half-life of Pu-244 is 82 million year and this isotope is dominated of natural Pluotnium.118.68.121.49 (talk) 12:10, 19 May 2010 (UTC)


 * Yes, but in order to be mononuclidic it has to be useful in weighing, and there's not enough Pu-244 around to weigh. Also, while it's perfectly true that all primordial Pu is Pu-244, this has been overwhelmed by artificial Pu-239 and Pu-240 environmental contamination. S  B Harris 16:57, 19 May 2010 (UTC)

Protactinium
Why protactinium is here? Two nuclides of Pa exist naturally, Pa-231 (family of U-235) and Pa-234/Pa-234m (family of U-238). --V1adis1av (talk) 13:04, 31 March 2011 (UTC)
 * Because Pa-234 has a half-live of 6 hours-- too short to be found naturally even as a decay product, or used in measurements of atomic weights, from nature nuclide sources. Enough Pa-231 exists in uranium beds (half life 32,000 years, about the same as plutonium-239) to be separable and useful as a mononuclidic standard, at least according to NIST, 2005. The half life limit is somewhat arbitrary, but 6 hours is certainly too small to find any weighable isotope in nature. S  B Harris 18:45, 31 March 2011 (UTC)

Structural balance
These isotopes are noted to all be OE's. Which means you start out with an unbalanced odd numbered neutron/proton pair structure. Then you have to balance it by the addition of an additional number of "extra neutrons", and the best balancing number is usually an odd number. But they can't be fully balanced, only nearly balanced, and as they get larger it becomes possible to nearly balance them with 2 different odd numbers of extra neutron numbers.WFPM (talk) 19:55, 14 April 2011 (UTC)

Thorium
Why is Th here? 230Th occurs in nature (especially in deep seawaters) and has a half-life of over 75000 years. IUPAC has reclassified it as a binuclidic (they write "bi-isotopic", but this is almost certainly a typo from the definitions given in these two Wikipedia articles) element. Double sharp (talk) 10:10, 25 September 2013 (UTC)

IUPAC
calls these monoisotopic, and excludes Th. Double sharp (talk) 14:36, 24 June 2016 (UTC)

Periodic table illustration
Krypton should have an orange rather than a black triangle, due to the recent observation of double electron capture of 78Kr. Double sharp (talk) 04:31, 6 April 2018 (UTC)

Color encoding
The figure is informative, but the key does not explain the significance of the cyan and magenta tiles. Charles Clark (talk) 06:12, 22 October 2022 (UTC)