Identifikatoren & physikalische Daten
| CAS No. | 7440-40-6 |
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| Summenformel | Bk |
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| Durchschnittliche Molmasse | 247,0703 g/mol |
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| Monoisotopische Masse | 247,07031 g/mol |
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| SMILES | [Bk] |
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| InChIKey | PWVKJRSRVJTHTR-UHFFFAOYSA-N |
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| PubChem CID | 23971 |
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| ChEBI | CHEBI:33391 |
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| DTXSID | DTXSID70225389 |
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Chemische & physikalische Eigenschaften
| Polarare Oberfläche (TPSA) | 0 |
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| H-Brücken-Donoren | 0 |
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| H-Brücken-Akzeptoren | 0 |
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| Frei drehbare Bindungen | 0 |
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| Schwere Atome | 1 |
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| Formalladung | 0 |
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| Komplexität | 0 |
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| Stoffklassen | Physical/Radiation -> Radionuclides |
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| Physical Description | A man-made radioactive metal with a melting point of 986 degrees CKnown isotopes have mass numbers of 240 and 242-251Bk-247 is the isotope with the longest half life[Merck Index # 1158] |
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| Schmelzpunkt | 986 ± 25° (Fahey)mp 1050° (Katz et al., loc. cit. vol. 2, p 1150) |
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| Siedepunkt | ~2630℃ [KAT86] |
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| Dichte | (calc) 14.78d (calc) 13.25 |
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| Aggregatzustand | hexagonal |
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| Farbe | hexagonal, hexane crystals, crystalline |
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| Bulk Modulus | 52.0 GPa |
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Sicherheit & Vorschriften
| Gefahrenübersicht | Most Important Radionuclide: Bk-247
Source: Nuclear reactors or particle acceleratorsHalf-Life: 1,400 years
Specific Activity (mCi/gm): 1.1
Decay Mode: Alpha
Internal Toxicity: Very High
Annual Limit on Intake: 0.0000009 mCi
Average Radiation Energy (MeV): Alpha 5.6Beta 0.061Gamma 0.11[Argonne]
[See Glossary for references.] See Radiation, ionizing. |
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Anwendungen & Verwendung
History
Berkelium [CAS: 7440-40-6], the atomic number is 97 and the chemical symbol is Bk. The name is derived from Berkeley, the town in California where the element was first synthesized in 1949 by the American scientific team Stanley G. Thompson, Albert Ghiorso, and Glenn T. Seaborg at the University of California, Berkeley, CA., using the nuclear reaction 241Am(4He, 2n) 243Bk. It is the eighth element in the Actinide series of the elements and was named in analogy with Terbium (for Ytterby the town in Sweden whose mine produced the ore), which is the eighth element in the Lanthanide series of the elements. The longest half-life associated with this unstable element is 1400 year 247Bk. See also Berkelium.
