![]() Note: This article, originally published in 1998, was updated in 2006 for the eBook edition. "It's Elemental: Astatine." Jefferson Lab. The CRC Handbook of Chemistry and Physics, 84th edition. Because of its similarities to iodine, which accumulates in the thyroid, it is believed that the element could be utilized to treat certain thyroid diseases. Researchers are investigating astatine as a means of treating various cancers (e.g., lethal brain tumors) and diseases. Additional compounds (HAt and CH 3At) have also been detected.īecause of its scarcity and short half-life, there were no commercial uses for astatine as of 2003. ![]() Astatine is known to form interhalogen compounds with bromine (AtBr), chlorine (AtCl), and iodine (AtI). Other isotopes have mass numbers ranging from 193 to 223 and half-lives ranging from 125 nanoseconds ( 213At) to 7.2 hours ( 211At). The most stable isotope of astatine is 210At, which has a half-life of 8.1 hours. ![]() Astatine can also be produced in a nuclear reactor by the method used by its discoverers, according to the following reaction: It is produced naturally when the elements uranium and thorium decay. The origin of the name "astatine" is the Greek word astatos, which means "unstable."Īstatine is found in only vanishingly small amounts in nature -it is believed that only 30 grams (1 ounce) of the element are present in Earth's crust at any one time. The name astatine comes from the Greek word astatos, which literally. MacKenzie, and Emilio Segr è of the University of California produced the element in 1940 by bombarding an isotope of bismuth ( 209Bi) with alpha particles. Use Youtube to practice the pronunciation of astatos in real conversation. This group includes chloride, bromine, iodine, and astatine.It has an atomic number of 9 and a density of 1.5127 g cm 3 at 188.13 ☌. Fluorine is the lightest element of Group 17 of the periodic table called halogens. This display is contained within crystal clear lucite acrylic.Astatine is a radioactive halogen (the heaviest of the halogen elements) and is a solid at room temperature. Kapp Jr., in Encyclopedia of Toxicology (Third Edition), 2014 Environmental Behavior, Fate and Routes and Pathways. Neither the most stable isotope astatine-210, nor the medically useful astatine-211, occur naturally they can only be produced synthetically. Much less than one gram is present at any given time in the Earth's crust. Named after the Greek word astatos, meaning "unstable". The bulk properties of astatine are not known with certainty, but many of them have been estimated based on the element's position on the periodic table. Astatine is likely to have a dark or lustrous appearance and could be a semiconductor or possibly a metal. MacKenzie, and Emilio Segrè at the University of California, Berkeley by barraging bismuth with alpha particles. A sample of the pure element has never been assembled, because any macroscopic specimen would be immediately vaporized by the heat of its own radioactivity. Astatine (after Greek astatos, meaning 'unstable') was first synthesized in 1940 by Dale R. Astatine's atomic number is 85 and its symbol is At. It is the rarest naturally occurring element in the Earth's crust, occurring only as the decay product of various heavier elements. All of the astatine's isotopes are short-lived the most stable is astatine-210, with a half-life of 8.1 hours.
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