Search results
Results from the WOW.Com Content Network
Astatine-218 was the first astatine isotope discovered in nature. [113] Astatine-219, with a half-life of 56 seconds, is the longest lived of the naturally occurring isotopes. [6] Isotopes of astatine are sometimes not listed as naturally occurring because of misconceptions [103] that there are no such isotopes, [114] or discrepancies in the ...
Astatine can be incorporated into organic molecules via halogen exchange, halodediazotation (replacing a diazonium group), halodeprotonation, or halodemetallation. Initial attempts to radiolabel proteins with 211 At exemplify its intermediate behaviour, as astatination (analogous to radioiodination) produces unstable results and it is instead ...
Structure of astatine monoiodide, one of the astatine interhalogens and the heaviest known diatomic interhalogen. Astatine is known to react with its lighter homologs iodine, bromine, and chlorine in the vapor state; these reactions produce diatomic interhalogen compounds with formulas AtI, AtBr, and AtCl. [4]
Astatine is a very rare radioactive chemical element with the chemical symbol At and atomic number 85. It occurs on Earth as the decay product of various heavier elements. All its isotopes are short-lived, with half-lives of 8.1 hours or less. Elemental astatine has never been viewed because a mass large enough to be seen by the naked eye would ...
This page was last edited on 12 November 2022, at 21:48 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may apply.
In 1950 astatine was described as a halogen and (therefore) a reactive nonmetal. [467] In 2013, on the basis of relativistic modelling, astatine was predicted to be a monatomic metal, with a face-centred cubic crystalline structure. [468] Several authors have commented on the metallic nature of some of the properties of astatine.
The halogens (/ ˈ h æ l ə dʒ ə n, ˈ h eɪ-,-l oʊ-,-ˌ dʒ ɛ n / [1] [2] [3]) are a group in the periodic table consisting of six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and the radioactive elements astatine (At) and tennessine (Ts), though some authors [4] would exclude tennessine as its chemistry is unknown and is theoretically expected to ...
Astatine (At) 85 ἄστατος (astatos) Greek "unstable" From Greek ἄστατος (astatos), meaning "unstable". · Former name alabamine (Ab) was an earlier proposed name for astatine Radon (Rn) 86 radium: Latin via German and English [57] Contraction of radium emanation, since the element appears in the radioactive decay of radium.