Roentgenium (Rg)
transition-metalExpected to be a Solid
Nguyên tử khối chuẩn
281 uCấu hình electron
[Rn] 7s2 5f14 6d9 (Dự đoán)Nhiệt độ nóng chảy
Không cóNhiệt độ sôi
Không cóKhối lượng riêng
2,87e+4 kg/m³Trạng thái oxi hóa
−1, +1, +3, +5Độ âm điện (Pauling)
Không cóNăng lượng ion hóa (lần 1)
Không cóNăm phát hiện
1994Bán kính nguyên tử
138 pmChi tiết
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.
Hình ảnh
Tính chất
Vật lý
- Bán kính nguyên tử (thực nghiệm)
- 138 pm So sánh Bán kính nguyên tử (thực nghiệm) của tất cả nguyên tố →
- Khối lượng riêng
- 2,87 × 104 kg/m³ So sánh Khối lượng riêng của tất cả nguyên tố →
Hóa học
- Ái lực electron
- 1,6 eV
- Trạng thái oxi hóa
- −1, +1, +3, +5 So sánh Trạng thái oxi hóa của tất cả nguyên tố →
- Electron hóa trị
- 2 So sánh Electron hóa trị của tất cả nguyên tố →
- Cấu hình electron
- [Rn] 7s2 5f14 6d9 (Dự đoán)
Nhiệt động lực học
Không có
Hạt nhân
- Proton
- 111 So sánh Proton của tất cả nguyên tố →
- Neutron
- 171 So sánh Neutron của tất cả nguyên tố →
- Các đồng vị đã biết
- 15 So sánh Các đồng vị đã biết của tất cả nguyên tố →
- Đồng vị bền
- 0 So sánh Đồng vị bền của tất cả nguyên tố →
- Số khối (đồng vị bền nhất)
- 282
- Đồng vị bền nhất
- Rg-282
- Năm phát hiện
- 1994
Độ phổ biến
Không có
Cấu trúc tinh thể
Không có
Cấu trúc electron
- Số electron trong mỗi lớp
- 14, 9, 2 So sánh Số electron trong mỗi lớp của tất cả nguyên tố →
Mã định danh
- Số CAS
- 54386-24-2 So sánh Số CAS của tất cả nguyên tố →
- InChI
- InChI=1S/Rg
- Khóa InChI
- LJROPTGWFUZRDB-UHFFFAOYSA-N
Cấu hình electron Dự đoán
——Không có dữ liệu cấu hình electron cho ion này.
Mô hình nguyên tử
Các đồng vị khác nhau về số neutron, khối lượng và độ bền — không khác nhau về cấu hình electron của nguyên tử trung hòa.
Không có
Mô hình nguyên tử minh họa, không theo tỷ lệ.
Dấu vân tay nguyên tử
Phổ phát xạ / hấp thụ
Phân bố đồng vị
Không có đồng vị bền.
| Số khối | Khối lượng nguyên tử (u) | Độ phổ biến tự nhiên | Chu kỳ bán rã |
|---|---|---|---|
| 279 Phóng xạ | 279,16272 ± 0,00051 | Không có | 170 ms |
| 282 Phóng xạ | 282,16912 ± 0,00072 | Không có | 130 giây |
| 285 Phóng xạ | 285,175771 ± 0,000644 | Không có | 30 giây |
| 274 Phóng xạ | 274,15525 ± 0,00019 | Không có | 20 ms |
| 281 Phóng xạ | 281,16636 ± 0,00089 | Không có | 19 giây |
Pha / Trạng thái
Không có dữ liệu pha/trạng thái
Không có dữ liệu pha/trạng thái
Hợp chất
Đồng vị (5)
| Số khối | Khối lượng nguyên tử (u) | Độ phổ biến tự nhiên | Chu kỳ bán rã | Kiểu phân rã | |
|---|---|---|---|---|---|
| 279 Phóng xạ | 279,16272 ± 0,00051 | Không có | 170 ms | α =100% | |
| 282 Phóng xạ | 282,16912 ± 0,00072 | Không có | 130 giây | α =100% | |
| 285 Phóng xạ | 285,175771 ± 0,000644 | Không có | 30 giây | α ?SF ? | |
| 274 Phóng xạ | 274,15525 ± 0,00019 | Không có | 20 ms | α ≈100% | |
| 281 Phóng xạ | 281,16636 ± 0,00089 | Không có | 19 giây | SF =87±0.8%α =13±0.8% |
Tính chất mở rộng
Bán kính cộng hóa trị (mở rộng)
- Bán kính cộng hóa trị (Pyykkö)
- 121 pm
- Bán kính cộng hóa trị (Pyykkö, liên kết đôi)
- 116 pm
- Bán kính cộng hóa trị (Pyykkö, liên kết ba)
- 118 pm
Các thang đánh số
- Mendeleev
- 74
Độ phân cực hóa và tán sắc
- Độ phân cực hóa lưỡng cực
- 32 a.u.
- Độ phân cực hóa lưỡng cực (độ không đảm bảo)
- 6 a.u.
Phân loại trạng thái oxi hóa
Dữ liệu tham khảo chuyên sâu
Các kiểu phân rã đồng vị (22)
| Đồng vị | Chế độ | Cường độ |
|---|---|---|
| 272 | A | 100% |
| 273 | A | — |
| 274 | A | 100% |
| 275 | A | — |
| 276 | A | — |
| 276 | SF | — |
| 277 | A | — |
| 277 | SF | — |
| 278 | A | 100% |
| 279 | A | 100% |
Dữ liệu bổ sung
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
Not Applicable
Tài liệu tham khảo (1)
- [5] Roentgenium https://education.jlab.org/itselemental/ele111.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
Not Applicable
Tài liệu tham khảo (1)
- [5] Roentgenium https://education.jlab.org/itselemental/ele111.html
Tài liệu tham khảo
(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.