Difference between revisions of "Polonium"
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'''Polonium''' (symbol: '''Po''') is a [[chemical element]], one of the [[chalcogen]]s. It is a silvery-white metal with a unique [[simple cubic structure]],<ref name="G&E"/> although it is rare that polonium or its compounds are encountered in weighable quantities. | '''Polonium''' (symbol: '''Po''') is a [[chemical element]], one of the [[chalcogen]]s. It is a silvery-white metal with a unique [[simple cubic structure]],<ref name="G&E"/> although it is rare that polonium or its compounds are encountered in weighable quantities. | ||
| − | Polonium has no stable isotopes, and the metal and all its compounds are intensely radioactive. The power output due to the radioactive decay of [[polonium-210]] is about {{nowrap|140 W g<sup>−1</sup>}}, which leads to considerable self-heating and which complicates the investigation of its properties with macroscopic quantities.<ref name="G&E"/> | + | Polonium has no stable isotopes, and the metal and all its compounds are intensely [[Radioactivity|radioactive]]. The power output due to the radioactive decay of [[polonium-210]] is about {{nowrap|140 W g<sup>−1</sup>}}, which leads to considerable self-heating and which complicates the investigation of its properties with macroscopic quantities.<ref name="G&E"/> |
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| + | ==History== | ||
| + | Polonium was discovered in 1898 by [[Marie Curie]] while she was investigating the radioactivity of [[pitchblende]]. The isolation of miligram quantities of polonium required the processing of over 15 tonnes of ore, and earned Marie Curie the [[Nobel Prize for Chemistry]] in 1911. The element was named after Curie's native Poland.<ref name="G&E"/> | ||
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| + | ==Occurrence and production== | ||
| + | The only naturally ocurring isotope of polonium is [[polonium-210]] (''t''<sub>½</sub> = 138.38 days), the penultimate member of the [[radium decay series]]. It occurs in [[uranium]] ores at about 0.1 mg per tonne of ore (a mass fraction of about 10<sup>−10</sup>). The overall abundance of polonium in crustal rocks can be estimated at about 3{{e|−10}} ppm.<ref name="G&E"/> | ||
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| + | Extraction of polonium from natural sources is impractical, and it is produced commercially by the [[neutron]] irradiation of [[bismuth]] in a nuclear reactor.<ref name="G&E"/> | ||
==Notes and references== | ==Notes and references== | ||
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Polonium (symbol: Po) is a chemical element, one of the chalcogens. It is a silvery-white metal with a unique simple cubic structure,[1] although it is rare that polonium or its compounds are encountered in weighable quantities.
Polonium has no stable isotopes, and the metal and all its compounds are intensely radioactive. The power output due to the radioactive decay of polonium-210 is about 140 W g−1, which leads to considerable self-heating and which complicates the investigation of its properties with macroscopic quantities.[1]
Contents
History
Polonium was discovered in 1898 by Marie Curie while she was investigating the radioactivity of pitchblende. The isolation of miligram quantities of polonium required the processing of over 15 tonnes of ore, and earned Marie Curie the Nobel Prize for Chemistry in 1911. The element was named after Curie's native Poland.[1]
Occurrence and production
The only naturally ocurring isotope of polonium is polonium-210 (t½ = 138.38 days), the penultimate member of the radium decay series. It occurs in uranium ores at about 0.1 mg per tonne of ore (a mass fraction of about 10−10). The overall abundance of polonium in crustal rocks can be estimated at about 3 × 10−10 ppm.[1]
Extraction of polonium from natural sources is impractical, and it is produced commercially by the neutron irradiation of bismuth in a nuclear reactor.[1]
Notes and references
Notes
- ↑ Atomic weight of polonium-210, which is by far the most commonly encountered isotope.
References
Further reading
- Polonium; Moyer, Harvey V., Ed.; United States Atomic Energy Commission: Oak Ridge, Tenn., 1956. TID-5221. doi:10.2172/4367751, <http://www.osti.gov/bridge/servlets/purl/4367751-nEJIbm/>.
External links
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See also the corresponding article on Wikipedia. |
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