Roentgenium (Rg)
transition-metalExpected to be a Solid
Standard Atomic Weight
[281]Electron configuration
[Rn] 7s2 5f14 6d9(predicted)Melting point
N/ABoiling point
N/ADensity
2.870000e+4 kg/m³Oxidation states
−1, +1, +3, +5Electronegativity (Pauling)
N/AIonization energy (1st)
Discovery year
1994Atomic radius
138 pmDetails
Roentgenium is a synthetic transactinide element in group 11, below gold. It has been made only one atom at a time in heavy-ion fusion experiments, and all confirmed isotopes are highly radioactive and short-lived. Its chemistry has not been established experimentally in bulk or solution. Relativistic calculations generally place it among the coinage metals, but with properties that may differ appreciably from lighter homologues.
Roentgenium does not occur naturally in the Earth’s crust. Roentgenium was first synthesized by an international team of scientists from the GSI in Darmstadt, Germany, the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, the Comenius University in Bratislava, Slovakia, and the University of Jyväskylä, Finland at the GSI Helmholtz Center for Heavy Ion Research in Darmstadt, Germany in 1994, using the nuclear reaction 209Bi (64Ni, n) 272Rg. The credit for the first synthesis was confirmed in 2003. The element was named after Wilhelm Conrad Roentgen (Fig. IUPAC.111.1), who discovered X-rays in 1895 [660], [661], [662]. Roentgenium has no known isotopic applications aside from scientific research.
Roentgenium is named after Wilhelm Conrad Röntgen.
Roentgenium was first produced by Peter Armbruster, Gottfried Münzenber and their team working at the Gesellschaft für Schwerionenforschung in Darmstadt, Germany in late 1994. They bombarded atoms of bismuth-209 with ions of nickel-64 with a device known as a linear accelerator. This produced three atoms of roentgenium-272, an isotope with a half-life of about 1.5 milliseconds (0.0015 seconds), and a free neutron. Roentgenium's most stable isotope, roentgenium-281, has a half-life of about 26 seconds and decays through spontaneous fission.
Discovered by Gesellschaft Schwerionenforschung (GSI) in Darmstadt, in 1994. Reasearch group of S. Hofmann, V. Ninov, F.P. Hessberger, P. Armbruster, H. Folger, G. Munzenberg, H.J. Schott, and others.
Images
Properties
Physical
Chemical
Thermodynamic
N/A
Nuclear
Abundance
N/A
Reactivity
N/A
Crystal Structure
N/A
Electronic Structure
Identifiers
Electron Configuration Predicted
——Electron configuration data not available for this ion.
Atomic model
Isotopes change neutron count, mass, and stability — not the electron configuration of a neutral atom.
N/A
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 |
|---|---|---|---|
| 279 Radioactive | 279.16272 ± 0.00051 | N/A | 170 ms |
| 282 Radioactive | 282.16912 ± 0.00072 | N/A | 130 seconds |
| 285 Radioactive | 285.175771 ± 0.000644 | N/A | 30 seconds |
| 274 Radioactive | 274.15525 ± 0.00019 | N/A | 20 ms |
| 281 Radioactive | 281.16636 ± 0.00089 | N/A | 19 seconds |
Phase / State
Phase/state data not available
Phase/state data not available
Compounds
Isotopes (5)
| Mass number | Atomic mass (u) | Natural abundance | Half-life | Decay mode | |
|---|---|---|---|---|---|
| 279 Radioactive | 279.16272 ± 0.00051 | N/A | 170 ms | α =100% | |
| 282 Radioactive | 282.16912 ± 0.00072 | N/A | 130 seconds | α =100% | |
| 285 Radioactive | 285.175771 ± 0.000644 | N/A | 30 seconds | α ?SF ? | |
| 274 Radioactive | 274.15525 ± 0.00019 | N/A | 20 ms | α ≈100% | |
| 281 Radioactive | 281.16636 ± 0.00089 | N/A | 19 seconds | SF =87±0.8%α =13±0.8% |
Extended Properties
Covalent Radii (Extended)
Numbering Scales
Polarizability & Dispersion
Oxidation State Categories
Advanced Reference Data
Isotope Decay Modes (22)
| Isotope | Mode | Intensity |
|---|---|---|
| 272 | A | 100% |
| 273 | A | — |
| 274 | A | 100% |
| 275 | A | — |
| 276 | A | — |
| 276 | SF | — |
| 277 | A | — |
| 277 | SF | — |
| 278 | A | 100% |
| 279 | A | 100% |
Additional Data
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
Not Applicable
References (1)
- [5] Roentgenium https://education.jlab.org/itselemental/ele111.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
Not Applicable
References (1)
- [5] Roentgenium https://education.jlab.org/itselemental/ele111.html
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.
Thomas Jefferson National Accelerator Facility (Jefferson Lab) is one of 17 national laboratories funded by the U.S. Department of Energy. The lab's primary mission is to conduct basic research of the atom's nucleus using the lab's unique particle accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF). For more information visit https://www.jlab.org/
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.
This section provides all form of data related to element Roentgenium.