Talk:Astatine

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Article changed over to new Wikipedia:WikiProject Elements format by maveric149. Elementbox converted 12:37, 10 July 2005 by Femto (previous revision was that of 07:39, 11 June 2005).

Contents 1 Information Sources 2 Ionization energy 3 Rarest? 4 Name 5 Half-life of 210At

[edit] Information Sources

Some of the text in this entry was rewritten from Los Alamos National Laboratory - Astatine. Additional text was taken directly from the Elements database 20001107 (via dict.org) and WordNet (r) 1.7 (via dict.org). Data for the table was obtained from the sources listed on the main page and Wikipedia:WikiProject Elements but was reformatted and converted into SI units.

[edit] Ionization energy

From the Village Pump

According to your web page, the first ionization energy of astatine is 20KJ/mol. But i have contacted many universities to check if the first ionization energy has been discovered, and so far all of them have denied of the idea. please contact me to tell me where you got your source for this info. My name is Maulik Shah and my email is: <EMAIL ADDRESS REMOVED>

Thanks

The number 20 is much less than the periodic trend set by Cl, Br and I would seem to predict. -Smack 23:53, 5 Jan 2004 (UTC)

I sent this by email, and was attempting to post it to the pump when my network went down. Smack gave his reply before I could do so...

Information on sources for the element tables is at Wikipedia:WikiProject Elements. The ionization energy for astatine came from the following secondary source: http://www.webelements.com/webelements/elements/text/At/ionz.html . WebElements cites their sources here: [1]. I suggest you look up those two references. It seems entirely possible to me that the ionisation energy was estimated numerically, but that the details of this estimation were lost somewhere between the initial publication and the posting on WebElements.com. (Also by email) -- Tim Starling 01:29, Jan 6, 2004 (UTC)

I looked it up in the Gmelin handbook for astatine. It gives a number of references to different calculations that predict the 1st ionization energy as around 9.4eV (about 907 kJ/mol, if I've done the calculation right). It doesn't seem to have yet been experimentally measured. Actually, looking at the webpage referenced about it actually gives it as 920 kJ/mol, I suspect a typo -- DrBob 23:46, 6 Jan 2004 (UTC)

[edit] Rarest?

Which element is truly "the rarest naturally occuring element in the world", francium or astatine? I do not know if there is a definite answer, but I believe the wording in one or both of these articles would be appropriate. (I placed this discussion in francium's talk page as well, so be sure to check up on that discussion too.)

According to the guinness book of world records astatine is the rarest naturally occuring element with only an estimated 6 ounces in the entire mass of earth.

So then should we take out the phrase "With the possible exception of francium,"?

Actually, the equilibrium mass of astatine (218At) in the earth crust is about 0,13 g whereas the mass of francium (223Fr) is about 340 g. The claim of the Guinness Book of Records (on 25 g of At in the earth crust) is wrong. --V1adis1av 18:25, 5 May 2006 (UTC)

The article on Lutetium states that this element is "the least abundant of all naturally-occurring elements". Correct me if I'm wrong, but isn't that essentially saying that that's also "the rarest naturally occuring element in the world"? TerraFrost 21:12, 8 July 2006 (UTC)

Not necessarily. You might have more Francium and Astatine in outer space, while a bunch of Lutetium could have accumalated up on Earth. But that's just a possible clause. Don't take anything I say as fact.--198.161.102.118 03:18, 21 September 2006 (UTC)

The nonsense in the lutetium article about being rare has been removed since. Femto 11:20, 21 September 2006 (UTC)

I suggest the longest lived Isotope of Astatine is not necessarily the naturally occurring one. Thus, a shorter lived Isotope might be the naturally occuring one. This is based upon the rule of thumb that shorter half-life = less abundant. It would be nice for someone to put in what the naturally occurring isotope is. How about it?

Oh and the answer to the question of the rarest element might just be Technetium. Since it has been found to occur on the earth in extraordinary circumstances. This depends upon what you mean, rarest on earth, or rarest in the universe.

[edit] Name

Why is it called Astatine? Jimpartame 11:29, 16 April 2006 (UTC)

From the History section: Greek astatos meaning "unstable", named 1940. No stable isotopes. That's all there seems to be behind it. Femto 12:20, 16 April 2006 (UTC)

[edit] Half-life of 210At

The article states a 8.1 hours half-life of ²¹⁰At. However, other sources, including lots of websites and the German Wikipedia, say it's 8.3 hours. Unfortunately, some other websites concur with the 8.1h figure so I am not entirely sure who's right. Does anyone have reliable sources? Aragorn2 15:32, 6 September 2006 (UTC)

All references cited at Talk:Isotopes of astatine say 8.1 h. Femto 17:20, 6 September 2006 (UTC)