Bohrium (Bh)
transition-metalSolid
Standard Atomic Weight
[270]Electron configuration
[Rn] 7s2 5f14 6d5Melting point
N/ABoiling point
N/ADensity
3.710000e+4 kg/m³Oxidation states
+3, +4, +5, +7Electronegativity (Pauling)
N/AIonization energy (1st)
Discovery year
1976Atomic radius
128 pmDetails
Bohrium is a synthetic transactinide element in group 7, below rhenium. It has no stable isotopes and has been made only atom by atom in heavy-ion nuclear reactions or as decay products of heavier superheavy nuclei. Its chemistry is known from a small number of rapid experiments and is consistent with a very heavy group 7 metal, with the +7 state especially important. No natural role or technological use is known.
Bohrium does not occur naturally in the Earth’s crust. Bohrium was first synthesized by German scientists at the GSI Center for Heavy Ion Research in Darmstadt, Germany in 1981 using the nuclear reaction 209Bi (54Cr, n) 262Bh. The element is named for Niels Bohr (Fig. IUPAC.107.1), the Nobel Prize winning physicist [649], [650]. Bohrium has no known isotopic applications aside from scientific research.
Bohrium is named after Niels Bohr.
First produced in 1976 by scientists working at the Joint Institute for Nuclear Research in Dubna, Russia, and later confirmed in 1981 by Peter Armbruster, Gottfried Münzenber and their team working at the Gesellschaft für Schwerionenforschung in Darmstadt, Germany, bohrium was produced by bombarding a target of bismuth-209 with ions of chromium-54. Bohrium's most stable isotope, bohrium-270, has a half-life of about 1 minute. It decays into dubnium-266 through alpha decay.
Formally known as Ns, Nielsbohrium
In 1976 Soviet scientists at Dubna announced they had synthesized element 107 by bombarding 204Bi with heavy nuclei of 54Cr. Reports say that experiments in 1975 had allowed scientists "to glimpse" the new element for 2/1000 s. A rapidly rotating cylinder, coated with a thin layer of bismuth metal, was used as a target. This was bombarded by a stream of 54Cr ions fired tangentially.
The existence of element 107 was confirmed by a team of West German physicists at the Heavy Ion Research Laboratory at Darmstadt, who created and identified six nuclei of element 107.
Images
Properties
Physical
Chemical
Thermodynamic
N/A
Nuclear
Abundance
N/A
Reactivity
N/A
Crystal Structure
N/A
Electronic Structure
Identifiers
Electron Configuration Predicted
Bh: 5f¹⁴ 6d⁵ 7s²[Rn] 5f¹⁴ 6d⁵ 7s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁶ 5f¹⁴ 6d⁵ 7s²Atomic model
Isotopes change neutron count, mass, and stability — not the electron configuration of a neutral atom.
Schematic atomic model, not to scale.
Atomic Fingerprint
Emission / Absorption Spectrum
Isotope Distribution
No stable isotopes.
| Mass number | Atomic mass (u) | Natural abundance | Half-life |
|---|---|---|---|
| 263 Radioactive | 263.12292 ± 0.00033 | N/A | 200 ms |
| 268 Radioactive | 268.12969 ± 0.00041 | N/A | 190 seconds |
| 262 Radioactive | 262.12297 ± 0.00033 | N/A | 84 ms |
| 276 Radioactive | 276.149169 ± 0.000644 | N/A | 60 seconds |
| 274 Radioactive | 274.14355 ± 0.00065 | N/A | 57 seconds |
Phase / State
Phase/state data not available
Atomic Spectra
Showing 10 of 96 Atomic Spectra. Sorted by ion charge (ascending).
Levels Holdings ?
| Ion | Charge | Levels |
|---|---|---|
| Bh I | 0 | 2 |
| Bh II | +1 | 2 |
| Bh III | +2 | 2 |
| Bh IV | +3 | 2 |
| Bh V | +4 | 2 |
| Bh VI | +5 | 2 |
| Bh VII | +6 | 2 |
| Bh VIII | +7 | 2 |
| Bh IX | +8 | 2 |
| Bh X | +9 | 2 |
Phase/state data not available
Compounds
Isotopes (5)
| Mass number | Atomic mass (u) | Natural abundance | Half-life | Decay mode | |
|---|---|---|---|---|---|
| 263 Radioactive | 263.12292 ± 0.00033 | N/A | 200 ms | α ? | |
| 268 Radioactive | 268.12969 ± 0.00041 | N/A | 190 seconds | α ?SF ? | |
| 262 Radioactive | 262.12297 ± 0.00033 | N/A | 84 ms | α ≈100%SF<20% | |
| 276 Radioactive | 276.149169 ± 0.000644 | N/A | 60 seconds | α ?SF ? | |
| 274 Radioactive | 274.14355 ± 0.00065 | N/A | 57 seconds | α =100% |
Extended Properties
Covalent Radii (Extended)
Numbering Scales
Polarizability & Dispersion
Oxidation State Categories
Advanced Reference Data
Isotope Decay Modes (32)
| Isotope | Mode | Intensity |
|---|---|---|
| 260 | A | 100% |
| 260 | B+ | — |
| 260 | SF | — |
| 261 | A | 100% |
| 261 | SF | — |
| 262 | A | 100% |
| 262 | SF | 20% |
| 263 | A | — |
| 264 | A | 86% |
| 264 | SF | 14% |
Additional Data
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
Not Applicable
References (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
Not Applicable
References (1)
References
(8)
Data deposited in or computed by PubChem
The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.
Element data are cited from the Atomic weights of the elements (an IUPAC Technical Report). The IUPAC periodic table of elements can be found at https://iupac.org/what-we-do/periodic-table-of-elements/. Additional information can be found within IUPAC publication doi:10.1515/pac-2015-0703 Copyright © 2020 International Union of Pure and Applied Chemistry.
The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.
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The periodic table at the LANL (Los Alamos National Laboratory) contains basic element information together with the history, source, properties, use, handling and more. The provenance data may be found from the link under the source name.
The periodic table contains NIST's critically-evaluated data on atomic properties of the elements. The provenance data that include data for atomic spectroscopy, X-ray and gamma ray, radiation dosimetry, nuclear physics, and condensed matter physics may be found from the link under the source name. Ref: https://www.nist.gov/pml/atomic-spectra-database
This section provides all form of data related to element Bohrium.