97
Bk
Berkelium
247
Atomic Number: 97
Atomic Weight: 247
Melting Point: 1323 K (1050°C or 1922°F)
Boiling Point: Unknown
Density: 14 grams per cubic centimeter
Phase at Room Temperature: Solid
Element Classification: Metal
Period Number: 7 Group Number: none Group Name: Actinide
Radioactive and Artificially Produced
What's in a name? Named for the city of Berkeley, California.
Say what? Berkelium is pronounced as BURK-lee-em.
History and Uses:
Berkelium was first produced by Stanley G. Thompson, Glenn T. Seaborg, Kenneth Street, Jr. and Albert Ghiorso working at the University of California, Berkeley, in December, 1949. They bombarded an isotope of americium, americium-241, with alpha particles with a device called a cyclotron. This created berkelium-243 and two free neutrons.
Berkelium's most stable isotope, berkelium-247, has a half-life of about 1,380 years. It decays into americium-243 through alpha decay.
The first visible amounts of a berkelium compound, berkelium chloride (BkCl3) was produced in 1962 and weighed about 3 billionths of a gram (0.000000003 grams). Berkelium oxychloride (BkOCl), berkelium fluoride (BkF3), berkelium dioxide (BkO2) and berkelium trioxide (BkO3) have been identified and studied with a method known as X-ray diffraction.
Since only small amounts of berkelium have ever been produced, there are no known uses for berkelium and its compounds outside of basic scientific research.
Estimated Crustal Abundance: Not Applicable
Estimated Oceanic Abundance: Not Applicable
Number of Stable Isotopes: 0
Ionization Energy: 6.23 eV
Oxidation States: +4, +3
Electron Shell Configuration:
1s2
2s2 2p6
3s2 3p6 3d10
4s2 4p6 4d10 4f14
5s2 5p6 5d10 5f9
6s2 6p6
7s2