โ–ธโ–ธ
  • ๐Ÿ‡ฌ๐Ÿ‡ง Astatine
  • ๐Ÿ‡จ๐Ÿ‡ณ ็ ˆ
  • ๐Ÿ‡ณ๐Ÿ‡ฑ Astaat
  • ๐Ÿ‡ซ๐Ÿ‡ท Astate
  • ๐Ÿ‡ฉ๐Ÿ‡ช Astat
  • ๐Ÿ‡ฎ๐Ÿ‡ฑ ืืกื˜ื˜ื™ืŸ
  • ๐Ÿ‡ฎ๐Ÿ‡น Astato
  • ๐Ÿ‡ฏ๐Ÿ‡ต ใ‚ขใ‚นใ‚ฟใƒใƒณ
  • ๐Ÿ‡ต๐Ÿ‡น Astato
  • ๐Ÿ‡ท๐Ÿ‡บ ะัั‚ะฐั‚
  • ๐Ÿ‡ช๐Ÿ‡ธ Astato
  • ๐Ÿ‡ธ๐Ÿ‡ช Astat

Astatine: the essentials

Astatine atoms have 85 electrons and the shell structure is 2.8.18.32.18.7. The ground state electronic configuration of neutral astatine is [Xe].4f14.5d10.6s2.6p5 and the term symbol of astatine is 2P3/2.

Astatine: description  

The longest-lived isotope, 210At, has a half-life of only 8.3 hours. There are about 20 isotopes known, all of which are radioactive. Astatine is a halogen and possibly accumulates in the thyroid like iodine.

astatine
This sample of uranite contains a vanishingly small amount of astatine. Image adapted with permission from Prof James Marshall's (U. North Texas, USA) Walking Tour of the elements CD.

Astatine: physical properties

More physical properties...

Astatine: heat properties

More thermochemical properties...

Astatine: atom sizes

More atomc size properties...

Astatine: electronegativities

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Astatine: orbital properties

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Astatine: abundances

More geological data...

Astatine: crystal structure

At crystal structure
The solid state structure of astatine is: bcc (body-centred cubic).

More crystallographic data...

Astatine: biological data

Astatine has no biological role.

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Astatine: uses

Uses...

Astatine: reactions

Reactions of astatine as the element with air, water, halogens, acids, and bases where known.

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Astatine: binary compounds

Binary compounds with halogens (known as halides), oxygen (known as oxides), hydrogen (known as hydrides), and other compounds of astatine where known.

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Astatine: compound properties

Bond strengths; lattice energies of astatine halides, hydrides, oxides (where known); and reduction potentials where known.

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Astatine: history

Astatine was discovered by Dale Corson, MacKenzie, Segre in 1940 at California, USA. Origin of name: from the Greek word "astatos" meaning "unstable".

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Astatine: isotopes

Isotope abundances of astatine
Isotope abundances of astatine with the most intense signal set to 100%.

More isotope and NMR data...

Astatine: isolation

Isolation: astatine is radioactive and essentially unavailable in nature. It is not possible to make other than in a nuclear reactor. Bombardment of the bismuth isotope 20983Bi with α-particles (helium nuclei, 42He) results in formation of shortlived astatine and neutrons. The bismuth target is cooled during irradiation to prevent the volatile astatine disappearing.

20983Bi + 42He → 21185At + 2 10n

The 211At isotope has a half life of just over 7 hours so it is necessary to work quickly with it! Available quantities are of the order of 0.001 mg.

Heating the bismuth target to 300-600°C under N2 results in a stream of the elemental astatine that can be collected on a cold glass finger.