Berkelium Notable Characteristics History Isotopes

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curium – berkelium – californium
Tb Bk
	Full table

Known properties

Name, Symbol, Number

Berkelium, Bk, 97

Chemical series

Actinides

Period, Block

7, f

Appearance

unknown; probably metallic,
silvery white or gray

Atomic weight

[247] amu]]

Electron configurationElectron configuration is the arrangement of electrons in an atom, molecule or other body. Specifically, it is the placement of electrons into atomic, molecular, or other forms of electron orbitals. Orbitals, states, and wavefunctions Since electrons are

[ RnAstatine Radon Xe Rn Uuo Full table General Name, Symbol, NumberRadon, Rn, 86 Chemical series Noble gases Group, Period, Block 18 (VIIIA), 6 , p Density, Hardness 9. 73 kg/m3 (273 K), NA Appearance colorless Atomic properties Atomic weight [222] amu Atomi] 5f⁹ 7 s²

e^-The electron (also called negatron commonly represented as e&minus is a subatomic particle. In an atom the electrons surround the nucleus of protons and neutrons in an electron configuration. Electrons have the smallest electrical charge and when they mov 's per energy levelAn energy level is a quantified stable energy, which a physical system can have; the term is most commonly used in reference to the electron configuration of electrons, in atoms or molecules. According to quantum theory, only certain energy levels are pos

2,8,18,32,27,8,2

State of matter

solid

Most stable isotopes

isoIsotopes are atoms of a chemical element whose nuclei have the same atomic number, Z but different atomic weights, A''. The word isotope meaning at the same place comes from the fact that isotopes are located at the same place on the periodic table. The a	NANatural abundance refers to the prevalence of different isotopes of an element as found in nature. The weighted (by natural abundance) average mass of these isotopes is the atomic weight listed for the element in the periodic table. The abundance of an el	half-life	DM	DE M eV	DP
²⁴⁵Bk	{syn.}	4.94 d	ε ε	0.810 6.455	²⁴⁵ Cm ²⁴¹ Am
²⁴⁶Bk	{syn.}	1.8 d	α ε	6.070 1.350	²⁴²Am ²⁴⁶Cm
²⁴⁷Bk	{syn.}	1380 y	α	5.889	²⁴³Am
²⁴⁸Bk	{syn.}	>9 y	α	5.803	²⁴⁴Am
²⁴⁹Bk	{syn.}	320 d	α SF β^-	5.526 0.125	²⁴⁵Am ²⁴⁹ Cf

Berkelium is a synthetic element in the periodic table that has the symbol Bk and atomic number 97. A radioactive metallic element in the actinide series, berkelium was first synthesized by bombarding americium with alpha particles ( helium ions) and was named after Berkeley, California. Berkelium was the fifth transuranic element to be synthesized.

1 Notable characteristics

Weighable amounts of berkelium-249 (half-life 314 days) make it possible to determine some of its properties using macroscopic quantities. As of 2004 it had not been isolated in its elemental form, but it is predicted to be a silvery metal that would easily oxidize in air at elevated temperatures and would be soluble in dilute mineral acid s.

X-ray diffraction techniques have been used to identify various berkelium compounds such as berkelium dioxide (BkO₂), berkelium fluoride (BkF₃), berkelium oxychloride (BkOCl), and berkelium trioxide (BkO₃). In 1962 visible amounts of berkelium chloride were isolated that weighed 3 billionth of a gram. This was the first time visible amounts of a pure berkelium compound were produced.

Like other actinides, berkelium bio-accumulates in skeletal tissue. This element has no known uses outside of basic research and plays no biological role.

2 History

Berkelium was first synthesized by Glenn T. Seaborg, Albert Ghiorso, Stanley G. Thompson, and Kenneth Street, Jr at the University of California, Berkeley in December 1949. The team used a cyclotron to bombard a milligram-sized target of americium-241 with alpha particles to produce berkelium-243 ( half-life 4.5 hours) and two free neutrons. One of the longest lived isotopes of the element, berkelium-249 (half-life 320 days), was later synthesized by subjecting a curium-244 target with an intense beam of neutrons.

3 Isotopes

19 radioisotopes of berkelium have been characterized, with the most stable being Bk-247 with a half-life of 1380 years, Bk-248 with a half-life of >9 years, and Bk-249 with a half-life of 320 days. All of the remaining radioactive isotopes have half-lifes that are less than 5 days, and the majority of these have half lifes that are less than 5 hours. This element also has 2 meta states, with the most stable being Bk-248m (t_½ 23.7 hours). The isotopes of berkelium range in atomic weight from 235.057 amu (Bk-235) to 254.091 amu (Bk-254).

4 References

5 External links

Chemical elements Actinides University of California, Berkeley

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