Information about Berkelium
- Bk redirects here. For other uses of the abbreviation, see BK.
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| Name, Symbol, Number | berkelium, Bk, 97 | ||||||||||||||||||||||||||||||||||||||||||||||||
| Chemical series | Actinide | ||||||||||||||||||||||||||||||||||||||||||||||||
| Group, Period, Block | n/a, 7, f | ||||||||||||||||||||||||||||||||||||||||||||||||
| Appearance | unknown, probably silvery white or metallic gray | ||||||||||||||||||||||||||||||||||||||||||||||||
| Standard atomic weight | (247) gmol−1 | ||||||||||||||||||||||||||||||||||||||||||||||||
| Electron configuration | [Rn] 5f9 7s2 | ||||||||||||||||||||||||||||||||||||||||||||||||
| Electrons per shell | 2, 8, 18, 32, 27, 8, 2 | ||||||||||||||||||||||||||||||||||||||||||||||||
| Physical properties | |||||||||||||||||||||||||||||||||||||||||||||||||
| Phase | solid | ||||||||||||||||||||||||||||||||||||||||||||||||
| Density (near r.t.) | (alpha) 14.78 gcm−3 | ||||||||||||||||||||||||||||||||||||||||||||||||
| Density (near r.t.) | (beta) 13.25 gcm−3 | ||||||||||||||||||||||||||||||||||||||||||||||||
| Melting point | (beta) 1259 K (986 °C, 1807 °F) | ||||||||||||||||||||||||||||||||||||||||||||||||
| Atomic properties | |||||||||||||||||||||||||||||||||||||||||||||||||
| Oxidation states | 3, 4 | ||||||||||||||||||||||||||||||||||||||||||||||||
| Electronegativity | 1.3 (scale Pauling) | ||||||||||||||||||||||||||||||||||||||||||||||||
| Ionization energies | 1st: 601 kJ/mol | ||||||||||||||||||||||||||||||||||||||||||||||||
| Miscellaneous | |||||||||||||||||||||||||||||||||||||||||||||||||
| Crystal structure | hexagonal close-packed | ||||||||||||||||||||||||||||||||||||||||||||||||
| Magnetic ordering | no data | ||||||||||||||||||||||||||||||||||||||||||||||||
| Thermal conductivity | (300 K) 10 Wm−1K−1 | ||||||||||||||||||||||||||||||||||||||||||||||||
| CAS registry number | 7440-40-6 | ||||||||||||||||||||||||||||||||||||||||||||||||
| Selected isotopes | |||||||||||||||||||||||||||||||||||||||||||||||||
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| References | |||||||||||||||||||||||||||||||||||||||||||||||||
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Berkelium (IPA: /bəˈkiːliəm/) 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 and the University of California, Berkeley. Berkelium was the fifth transuranic element to be synthesized.
Notable characteristics
Weighable amounts of 249Bk (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 acids.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 (BkCl3) were isolated that weighed 3 billionths 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.
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 241Am with alpha particles to produce 243Bk (half-life 4.5 hours) and two free neutrons. One of the longest lived isotopes of the element, 249Bk (half-life 330 days), was later synthesized by subjecting a 244Cm target with an intense beam of neutrons.Isotopes
19 radioisotopes of berkelium have been characterized, with the most stable being 247Bk with a half-life of 1380 years, 248Bk with a half-life of >9 years, and 249Bk with a half-life of 330 days. All of the remaining radioactive isotopes have half-lives that are less than 5 days, and the majority of these have half-lives that are less than 5 hours. This element also has 2 meta states, with the most stable being 248mBk (t½ 23.7 hours). The isotopes of berkelium range in atomic weight from 235.057 u (235Bk) to 254.091 u (254Bk).References
External links
BK may be in reference to:
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- Bad Kid (Bad Kid)
- Bagsværd Kostskole og Gymnasium, a Danish private school
- Beekeeper
- Ben Kennedy, an Australian Rugby League player
- Berkelium (symbol Bk)
- Beverley Knight
- BK (musician)
- Blue Kaffee
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Curium (IPA: /ˈkjuːriəm/) is a synthetic chemical element with the symbol Cm and atomic number 96.
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3, 4
Electronegativity 1.3 (scale Pauling)
Ionization energies 1st: 608 kJ/mol
Miscellaneous
CAS registry number 7440-71-3
Selected isotopes
Main article: Isotopes of californium
iso NA half-life DM DE (MeV) DP
248Cf syn 333.
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Electronegativity 1.3 (scale Pauling)
Ionization energies 1st: 608 kJ/mol
Miscellaneous
CAS registry number 7440-71-3
Selected isotopes
Main article: Isotopes of californium
iso NA half-life DM DE (MeV) DP
248Cf syn 333.
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Terbium (IPA: /ˈtɛː(r)biəm/) is a chemical element in the periodic table that has the symbol Tb and atomic number 65.
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<onlyinclude> This is a list of chemical elements, sorted by name and color coded according to type of element.
Given is each element's element symbol, atomic number, atomic mass or most stable isotope, and group and period numbers on the periodic table.
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Given is each element's element symbol, atomic number, atomic mass or most stable isotope, and group and period numbers on the periodic table.
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<onlyinclude> This is a list of chemical elements by symbol, including the current signification used to identify the chemical elements as recognized by the International Union of Pure and Applied Chemistry, as well as proposed and historical signs.
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A table of chemical elements ordered by atomic number and color coded according to type of element. Given is each element's name, element symbol, group and period, Chemical series, and atomic mass (or most stable isotope).
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A group, also known as a family, is a vertical column in the periodic table of the chemical elements. There are 18 groups in the standard periodic table.
The modern explanation of the pattern of the periodic table is that the elements in a group have similar
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The modern explanation of the pattern of the periodic table is that the elements in a group have similar
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The actinide (or actinoid) series encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table, with atomic numbers 89 - 103[1]. The actinide series derives its name from the first element in the series, actinium.
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A group, also known as a family, is a vertical column in the periodic table of the chemical elements. There are 18 groups in the standard periodic table.
The modern explanation of the pattern of the periodic table is that the elements in a group have similar
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The modern explanation of the pattern of the periodic table is that the elements in a group have similar
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Periods:]] 1 2 3 4 5 6 7 8
Series Alkalis Alkaline earths Lanthanides Actinides Transition metals Poor metals Metalloids Nonmetals Halogens Noble gases
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Series Alkalis Alkaline earths Lanthanides Actinides Transition metals Poor metals Metalloids Nonmetals Halogens Noble gases
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A block of the periodic table of elements is a set of adjacent groups. The respective highest-energy electrons in each element in a block belong to the same atomic orbital type.
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group number of lanthanides and actinides. There is no pre-existing physical entity for a "group" of elements. The notion is simply a convenient classification, since some elements have similar periodicities in their properties.
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A period 7 element is one of the chemical elements in the seventh row (or period) of the periodic table of the elements.
This period contains the heaviest element which occurs naturally on earth, uranium.
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This period contains the heaviest element which occurs naturally on earth, uranium.
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The f-block of the periodic table of the elements consists of those elements (sometimes referred to as the inner transition elements) for which, in the atomic ground state, the highest-energy electrons occupy f-orbitals.
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Color or colour[1] (see spelling differences) is the visual perceptual property corresponding in humans to the categories called red, yellow, blue, black, etc.
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atomic mass (ma) is the mass of an atom at rest, most often expressed in unified atomic mass units.[1] The atomic mass may be considered to be the total mass of protons, neutrons and electrons in a single atom (when the atom is motionless).
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To help compare different orders of magnitude, the following list describes various mass levels between 10−36 kg and 1053 kg.
Factor (kg) Value Item
10−36 1.
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Factor (kg) Value Item
10−36 1.
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electron configuration is the arrangement of electrons in an atom, molecule, or other physical structure (e.g., a crystal). Like other elementary particles, the electron is subject to the laws of quantum mechanics, and exhibits both particle-like and wave-like nature.
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Radon (IPA: /ˈreɪdɒn/) is a chemical element that has the symbol Rn and atomic number 86. Radon is a radioactive noble gas that is formed by the decay of radium.
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Electron
Theoretical estimates of the electron density for the first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density
Composition: Elementary particle
Family: Fermion
Group: Lepton
Generation: First
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Theoretical estimates of the electron density for the first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density
Composition: Elementary particle
Family: Fermion
Group: Lepton
Generation: First
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An electron shell, also known as a main energy level, is a group of atomic orbitals with the same value of the principal quantum number n. Electron shells are made up of one or more electron subshells, or sublevels
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In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i.e. density, crystal structure, index of refraction, and so forth).
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A solid object is in the states of matter characterized by resistance to deformation and changes of volume. At the microscopic scale, a solid has these properties :
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- The atoms or molecules that comprise the solid are packed closely together.
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In physics, density is mass m per unit volume V—how heavy something is compared to its size. A small, heavy object, such as a rock or a lump of lead, is denser than a lighter object of the same size or a larger object of the same weight, such as pieces of
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Room temperature (also referred to as ambient temperature) is a common term to denote a certain temperature within enclosed space at which human beings are accustomed.
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In physics, density is mass m per unit volume V—how heavy something is compared to its size. A small, heavy object, such as a rock or a lump of lead, is denser than a lighter object of the same size or a larger object of the same weight, such as pieces of
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Room temperature (also referred to as ambient temperature) is a common term to denote a certain temperature within enclosed space at which human beings are accustomed.
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The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. Although the phrase would suggest a specific temperature and is commonly and incorrectly used as such in most textbooks and literature, most crystalline compounds
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