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General information about Astatine |
| Astatine |
| At |
| 85 |
| Halogens |
| 17 |
| 6 |
| p |
| black solid (presumed) |
| (210) g·mol-1 |
1s2 2s2p6 3s2p6d10 4s2p6d10f14
5s2p6d10 6s2p5 |
| 2, 8, 18, 32, 18, 7 |
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Physical properties of Astatine |
| solid |
| ? |
| 575(K), 302°C, 576°F |
| 610(K), 337°C, 639°F |
| ? |
| ? |
| 114 kJ·mol-1 |
| 40 kJ·mol-1 |
| ? J·mol-1·K-1 |
| 2.2 (Pauling scale) |
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Atomic structure of Astatine |
| 1.43 Å |
| ? cm³/mol |
| 1.45 Å |
| ? |
| ? |
| 62 (+7e) |
| 6p5 |
| 85 |
| 125 |
| 85 |
| -1, 1, 3, 5, 7 |
| 6s2p5 |
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Electron dot
model |
Other languages |
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| Latin: |
Astatium |
| Czech: |
Astat |
| Croatian: |
Astat |
| French: |
Astatine |
| German: |
Astatin - r |
| Italian: |
Astato |
| Norwegian: |
Astat |
| Portuguese: |
Astato |
| Spanish: |
Astato |
| Swedish: |
Astat |
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| Element |
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85 |
2
8
18
32
18
7
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At |
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(210) |
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Brief description |
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Astatine has a melting point of 302C, an estimated boiling point of 337C, with probable valences of 1, 3, 5, or 7. Astatine possesses characteristics common to other halogens. It behaves most similarly to iodine, except that At exhibits more metallic properties. The interhalogen molecules AtI, AtBr, and AtCl are known, although it has not been determined whether or not astatine forms diatomic At2. HAt and CH3At have been detected. Astatine probably is capable of accumulating in the human thyroid gland.
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Uses of Astatine |
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Astatine was first synthesized by Corson, MacKenzie, and Segre at the University of California in 1940 by bombarding bismuth with alpha particles. Astatine may be produced by bombarding bismuth with energetic alpha particles to produce At-209, At-210, and At-211. These isotopes can be distilled from the target upon heating it in air. Small quantities of At-215, At-218, and At-219 occur naturally with uranium and thorium isotopes. Trace amounts of At-217 exist in equilibrium with U-233 and Np-239, resulting from the interaction between thorium and urainuam with neutrons. The total amount of astatine present in the Earth's crust is less than 1 ounce.
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Hystory of Astatine |
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- Discoverer: D.R. Corson, K.R. MacKenzie, E. Segre
- Discovery Location: United States
- Discovery Year: 1940
- Name Origin: Greek astatos, unstable
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