Astatine
Seldom found in nature.
| Atomic Number: |
85 |
| Atomic Symbol: |
At |
| Atomic Weight: |
210 |
| Electron Configuration: |
2-8-18-32-18-7 |
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History
(Gr. astatos, unstable) Synthesized in 1940 by D.R. Corson, K.R. MacKenzie, and E. Segre at the University of California by bombarding bismuth with alpha particles. The longest-lived isotopes, with naturally occurring uranium and thorium isotopes, and traces of 217At are equilibrium with 233U and 239Np reulting from interation of thorium and uranium with naturally produced neutrons. The total amount of astatine present in the earth's crust, however, is less than 1 oz.
Production
Astatine can be produced by bombarding iodine. Astatine is said to be more metallic than iodine, and, like iodine, it probably accumulates in the thyroid gland. Workers at the Brookhaven National Laboratory have recently used reactive scattering in crossed molecular beams to identify and measure elementary reactions involving astatine.
Sources:
- CRC Handbook of Chemistry and Physics
- American Chemical Society.
Last Updated: 12/19/97
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