Periodic Table -> Berkelium


Berkelium Details

Berkelium Symbol: Bk

Berkelium Atomic Number: 97

Berkelium Atomic Weight: (247)

What is Berkelium?

Berkelium (atomic number 97, symbol Bk) is a synthetic element, named under Berkley in California where the Radiation Laboratory of the University of Carolina is found, in which the element was discovered. Berkelium was discovered after americium, curium, plutonium, and neptunium and belongs to the transuranium and actinide series.

Berkelium is a silvery-white and soft radioactive metal. No practical uses have been found so far, outside of scientific research. Studies are directed at the synthesis of transactinides and transuranic elements. One isotope, berkelium-249 is safe to be handled because it emits low-energy electrons. Its half-life is 330 days after which it decays to californium-249. The latter is a dangerous and strong emitter of alpha particles. This fact is important to know because the formation of californium is associated with self-heating, radiation damage, and chemical contamination.

The element was first produced in 1949 by Albert Ghiorso, Kenneth Street, Jr., Glenn T. Seaborg, and Stanley G. Thompson. They bombarded americium-241, which is an isotope of americium, with a device called cyclotron, using alpha particles. In this way, 2 free neutrons and berkelium-243 were formed.

The most stable isotope of berkelium is berkelium-247, with alpha decay transforming it to americium-243. Its half-life has been reported at around 1,380 years.

Berkelium chloride, which is a berkelium compound, was first created in 1962. Other compounds have been identified and researched as well through X-ray diffraction, including berkelium dioxide, berkelium fluoride, berkelium oxychloride, and berkelium trioxide. There are no known applications of the compounds of berkelium, apart from scientific research. Compounds can be generally divided into halides, oxides, organometallic compounds, and inorganic compounds. Berkelium (III) and berkelium (IV) fluoride are halides. Berkelium (III) has 2 crystalline structures and a yellow-green color. Berkelium (III) is an ionic, yellow-green solid, which is isotypic with zirconium (IV) fluoride and uranium tetrafluoride.

The boiling point, melting point, Vanderwaals radius, and ionic radius are unknown and so is its electronegativity according to Pauling. There are some 10 isotopes and all of them have been found to be radioactive. Berkelium does not occur naturally and is not present in the earth’s crust. For this reason, it does not pose hazard to human health. Given their radioactivity, the isotopes of berkelium involve health hazards, although they can be produced only in laboratory conditions as of yet. The following considerations involve radioactivity, however. The development and production of nuclear technology has been associated with small and substantial releases of radioactivity in the seas, oceans, soil, and atmosphere. Radiation affects species and passes through the food chain, subjecting humans and animal life to its damaging effects.

This rare radioactive element is of no commercial importance. Berkelium has nuclear fission properties but they are different from those exhibited by californium and curium. These properties indicate that berkelium will not perform well when used as a fuel in nuclear reactors. Berkelium-249 has been researched to this purpose, but its fission cross section was found to be low for thermal neutrons. Berkelium-247 has the ability to maintain chain reactions in a fast neutron reactor and a thermal-neutron, but its production involves some complex processes. Its availability was found to be significantly lower compared to its critical mass. Finally, there is some evidence that it may accumulate in the skeletal system.

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