Roentgenium (Rg)
transition-metalExpected to be a Solid
Masse atomique relative standard
281 uConfiguration électronique
[Rn] 7s2 5f14 6d9 (Prédit)Point de fusion
N/DPoint d’ébullition
N/DMasse volumique
2,87e+4 kg/m³États d’oxydation
−1, +1, +3, +5Électronégativité (Pauling)
N/DÉnergie d’ionisation (1re)
N/DAnnée de découverte
1994Rayon atomique
138 pmDétails
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.
No macroscopic sample of roentgenium has ever been prepared, so its appearance is unknown. A bulk metal, if it could exist long enough, is expected from theory to be dense and metallic, but color, surface behavior, and ordinary physical constants have not been measured.
Roentgenium has no practical, commercial, medical, or industrial use. Its only use is in nuclear research, where individual atoms and their decay chains help test models of heavy-element formation, nuclear stability, and alpha decay. Experiments involving roentgenium also support the identification of neighboring superheavy nuclei, but the element is not available as a material for devices, tracers, or chemical applications.
Since only a few atoms of roentgenium have ever been produced, it currently has no uses outside of basic scientific research.
No confirmed roentgenium compound has been isolated or characterized. The element is expected to show group 11 chemistry in some respects, but strong relativistic effects make detailed predictions uncertain. The +1 and +3 oxidation states are commonly discussed in theoretical work, with possible analogies to gold compounds such as gold(III) chloride, AuCl₃, rather than to the more stable simple chemistry of copper or silver. Proposed species such as roentgenium fluorides or chlorides remain predictions, not observed substances.
See more information at the Roentgenium compound page.
The safety properties of roentgenium are governed by radioactivity rather than ordinary chemical toxicity. Known isotopes decay rapidly, mainly through alpha decay and spontaneous fission pathways within decay chains. The quantities produced are far below a macroscopic hazard under normal laboratory containment, but any experiment requires specialized radiological controls for heavy-ion target materials, recoil products, and short-lived radioactive daughters.
Roentgenium has no confirmed natural occurrence and no environmental cycle. Any atoms produced in a laboratory decay before they could disperse or participate in ordinary geochemical processes. Environmental relevance is therefore limited to controlled accelerator facilities and to the management of irradiated targets, catcher foils, and associated radioactive residues from superheavy-element experiments.
Roentgenium is not a commodity and has no market price, supply chain, or recycling practice. Production requires a heavy-ion accelerator, rare target materials, and long experiments with extremely low atom yields. The element is identified through decay correlations rather than collected as a product. Economic considerations are those of publicly or institutionally funded nuclear-physics research, including accelerator time, target preparation, detector systems, and radiological handling.
Made by bombarding bismuth-209 with nickel-60.
Roentgenium is not expected to be a persistent cosmic element because its known isotopes are too unstable. If nuclei with 111 protons are formed transiently in extreme nucleosynthetic environments, they would decay quickly unless an unknown much longer-lived isotope exists. No roentgenium has been detected in stars, meteorites, planets, or terrestrial minerals.
- Roentgenium was named in honor of Wilhelm Conrad Röntgen, discoverer of X-rays.
- Its identification relies on linking a few decay events to known daughter nuclei.
- The longest-lived confirmed isotopes still have half-lives far too short for chemical stockpiles.
- Roentgenium lies in the same periodic-table group as copper, silver, and gold.
- Chemical experiments have not yet established a measured oxidation state for roentgenium.
Images
Propriétés
Propriétés physiques
- Rayon atomique (empirique)
- 138 pm Comparer : Rayon atomique (empirique) de tous les éléments →
- Masse volumique
- 2,87 × 104 kg/m³ Comparer : Masse volumique de tous les éléments →
Propriétés chimiques
- Affinité électronique
- 1,6 eV
- États d’oxydation
- −1, +1, +3, +5 Comparer : États d’oxydation de tous les éléments →
- Électrons de valence
- 2 Comparer : Électrons de valence de tous les éléments →
- Configuration électronique
- [Rn] 7s2 5f14 6d9 (Prédit)
Propriétés thermodynamiques
N/D
Propriétés nucléaires
- Protons
- 111 Comparer : Protons de tous les éléments →
- Neutrons
- 171 Comparer : Neutrons de tous les éléments →
- Isotopes connus
- 15 Comparer : Isotopes connus de tous les éléments →
- Isotopes stables
- 0 Comparer : Isotopes stables de tous les éléments →
- Nombre de masse (isotope le plus stable)
- 282
- Isotope le plus stable
- Rg-282
- Année de découverte
- 1994
Abondance
N/D
Structure cristalline
N/D
Structure électronique
- Électrons par couche
- 14, 9, 2 Comparer : Électrons par couche de tous les éléments →
Identifiants
- Numéro CAS
- 54386-24-2 Comparer : Numéro CAS de tous les éléments →
- InChI
- InChI=1S/Rg
- Clé InChI
- LJROPTGWFUZRDB-UHFFFAOYSA-N
Configuration électronique Prédit
——Données de configuration électronique indisponibles pour cet ion.
Modèle atomique
Les isotopes diffèrent par leur nombre de neutrons, leur masse et leur stabilité — pas par la configuration électronique de l’atome neutre.
N/D
Modèle atomique schématique, non à l’échelle.
Empreinte atomique
Spectre d’émission / d’absorption
Distribution isotopique
Aucun isotope stable.
| Nombre de masse | Masse atomique (u) | Abondance naturelle | Demi-vie |
|---|---|---|---|
| 279 Radioactif | 279,16272 ± 0,00051 | N/D | 170 ms |
| 282 Radioactif | 282,16912 ± 0,00072 | N/D | 130 secondes |
| 285 Radioactif | 285,175771 ± 0,000644 | N/D | 30 secondes |
| 274 Radioactif | 274,15525 ± 0,00019 | N/D | 20 ms |
| 281 Radioactif | 281,16636 ± 0,00089 | N/D | 19 secondes |
Phase / État
Données de phase ou d’état indisponibles
Données de phase ou d’état indisponibles
Composés
Isotopes (5)
| Nombre de masse | Masse atomique (u) | Abondance naturelle | Demi-vie | Mode de désintégration | |
|---|---|---|---|---|---|
| 279 Radioactif | 279,16272 ± 0,00051 | N/D | 170 ms | α =100% | |
| 282 Radioactif | 282,16912 ± 0,00072 | N/D | 130 secondes | α =100% | |
| 285 Radioactif | 285,175771 ± 0,000644 | N/D | 30 secondes | α ?SF ? | |
| 274 Radioactif | 274,15525 ± 0,00019 | N/D | 20 ms | α ≈100% | |
| 281 Radioactif | 281,16636 ± 0,00089 | N/D | 19 secondes | SF =87±0.8%α =13±0.8% |
Propriétés étendues
Rayons covalents (données étendues)
- Rayon covalent (Pyykkö)
- 121 pm
- Rayon covalent (Pyykkö, liaison double)
- 116 pm
- Rayon covalent (Pyykkö, liaison triple)
- 118 pm
Échelles de numérotation
- Mendeleev
- 74
Polarisabilité et dispersion
- Polarisabilité dipolaire
- 32 a.u.
- Polarisabilité dipolaire (incertitude)
- 6 a.u.
Catégories d’états d’oxydation
Données de référence avancées
Modes de désintégration des isotopes (22)
| Isotope | Mode | Intensité |
|---|---|---|
| 272 | A | 100% |
| 273 | A | — |
| 274 | A | 100% |
| 275 | A | — |
| 276 | A | — |
| 276 | SF | — |
| 277 | A | — |
| 277 | SF | — |
| 278 | A | 100% |
| 279 | A | 100% |
Données complémentaires
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
Not Applicable
Références (1)
- [5] Roentgenium https://education.jlab.org/itselemental/ele111.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
Not Applicable
Références (1)
- [5] Roentgenium https://education.jlab.org/itselemental/ele111.html
Références
(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.