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WikiProject Elements (Rated FA-class, High-importance)
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I (Rmrfstar) believe that the information included in these books should be incorporated into this article ASAP. Unfortunately, they're not easy to find...

Electronegativity: The Pauling scale is the most commonly used system for electronegativity, and most complete electronegativity lists use it. These lists also put francium as the lowest electronegativity with 0.7. However, some of the reported values may be estimated rather than calculated. The Allen scale may be a more complete system, and it places caesium as the least electronegative element. However, it is difficult to find lists of Allen electronegativity values to confirm this. There seems to be no one source which says all of that, so for now, the Pauling value will remain, unless a better source can be found.

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Article changed over to Wikipedia:WikiProject Elements format by User:maveric149. Elementbox converted 10:05, 15 July 2005 by Femto (previous revision was that of 15:55, 10 July 2005).

Information Sources[edit]

Some of the text in this entry was rewritten from Los Alamos National Laboratory - Francium. Additional text was taken directly from the Elements database 20001107, and Webster's Revised Unabridged Dictionary (1913). Other information was obtained from the sources listed on the main page but was reformatted and


I am no expert in this subject, but maybe we could change the phrase "making it possibly the rarest elements in the crust, along with astatine." to "making it one of the rarest elements in the crust, next to astatine." See astatine talk page for more info.

Most unstable?[edit]

The article says

"Francium is the most unstable of the naturally occurring elements: its most stable isotope, francium-223, has a half-life of only 22 minutes. In contrast, astatine, the second-least stable naturally occurring element, has a half-life of 8.5 hours."

However, the astatine article says

"Astatine-219, with a half-life of 56 seconds, is the longest lived of the naturally occurring isotopes."

So, in terms of those isotopes that actually occur in nature, astatine is less stable than francium. Perhaps some clarification is in order? (talk) 03:15, 18 August 2016 (UTC)

Fair point. Because of this complication I would note that Fr-223 has 22 minutes and that its alpha daughter At-219 with 56 s is the longest-lived natural At isotope, though synthetic At-210 is far longer-lived. (And this is why I tend not to think of At and Fr, along with Tc, Pm, Np, and Pu, as natural at all: they either need very rare processes to make with our pitiful neutron flux today along with the low SF rates of uranium, or just don't live long enough and anyway come from obscure side branches of the natural decay chains, unlike primordial Th and U as well as secondary Po, Rn, Ra, Ac, and Pa that are a permanent fixture of the Earth as long as Th and U are still around.) Double sharp (talk) 05:23, 18 August 2016 (UTC)
 Done Double sharp (talk) 12:58, 18 August 2016 (UTC)

I finally get why francium is more common than astatine, astatine is longer lived, but that isotope is synthetic. The longest lived natural astatine is not as long lived as francium. 32ieww (talk) 02:09, 14 February 2017 (UTC) 32ieww (talk) 02:09, 14 February 2017 (UTC)

Wait a minute. I typed in 4 tildes, but it signed twice!32ieww (talk) 02:10, 14 February 2017 (UTC) 32ieww (talk) 02:10, 14 February 2017 (UTC)

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