Oganesson (Og)
noble-gasExpected to be a Gas
標準原子量
[294]電子配置
[Rn] 7s2 7p6 5f14 6d10 (予測値)融点
データなし沸点
-243.15 °C密度
7000 kg/m³酸化数
−1, 0, +1, +2, +4, +6電気陰性度（Pauling）
データなし第1イオン化エネルギー
データなし発見年
2006原子半径
データなし詳細
Oganesson is a synthetic element at the end of period 7 and is placed in group 18 with the noble gases. It has been made only atom by atom in heavy-ion fusion experiments, with the best-established isotope, ²⁹⁴Og, decaying in about a millisecond. Its chemistry has not been observed directly. Relativistic calculations suggest that it may be far less inert than lighter noble gases.
Oganesson does not occur naturally in the Earth’s crust. The name oganesson and symbol Og are the accepted ones for element 118. The name is in line with the tradition of honoring a scientist and recognizes Prof. Yuri Oganessian (Fig. IUPAC.118.1; born 1933) for his pioneering contribution to trans-actinoid element research. His many achievements include the discovery of super-heavy elements and significant advances in the nuclear physics of super-heavy nuclei, including experimental evidence for the “island of stability.”
In 2005, experiments were performed in Dubna’s U-400 cyclotron, where 48Ca bombarded a spinning target of 249Cf at nearly 3×104 km/s to produce oganesson. With the success of creating oganesson, scientists from Livermore and Joint Institute for Nuclear Research (JINR) are starting experiments to create element 120 by bombarding a 244Pu target with a beam of 58Fe [680], [681], [682], [683]. Oganesson has no known isotopic applications aside from scientific research.
On October 16, 2006, scientists working at the Joint Institute for Nuclear Research in Dubna, Russia, along with scientists from the U.S. Department of Energy's Lawrence Livermore National Laboratory, announced the creation of oganesson. They produced oganesson by bombarding atoms of californium-249 with ions of calcium-48. This produced oganesson-294, an isotope with a half-life of about 0.89 milliseconds (0.00089 seconds), and three free neutrons. The californium target was irradiated with a total of 1.6*1019 calcium ions over the course of 1080 hours, resulting in the production of three atoms of oganesson. Oganesson's most stable isotope, oganesson-294, has a half-life of about 0.89 milliseconds. It decays into livermorium-290 through alpha decay.
On Novemer 28th, 2016, element 118 was named Oganesson with the symbol (Og). The name was proposed by the Joint Institute for Nuclear Research, Dubna (Russia) and Lawrence Livermore National Laboratory (USA). It honors Professor Yuri Oganessian (born 1933) for his pioneering contributions to transactinoid elements research.
No macroscopic sample of oganesson has ever existed, so its appearance, density, melting point, and boiling point are not experimentally known. Predictions often treat it as a condensed, highly polarizable substance under ordinary conditions, but this remains theoretical.
Oganesson has no practical, commercial, medical, or industrial use. Its value is confined to nuclear research, where a few atoms can test models of superheavy nuclei, alpha decay, spontaneous fission, and the limits of the periodic table. The element cannot be stored or accumulated in useful quantities because its known nuclei decay almost immediately after formation.
Since only a few atoms of oganesson have ever been produced, it currently has no uses outside of basic scientific research.
No compound of oganesson has been experimentally prepared or characterized. Its possible chemistry is inferred from relativistic quantum calculations, which predict unusually strong spin-orbit effects and high polarizability for a group 18 element. Hypothetical species such as oganesson difluoride (OgF₂), oganesson tetrafluoride (OgF₄), and oxides have been discussed, but their stability, structures, and oxidation states are not established by experiment.
See more information at the Oganesson compound page.
The immediate hazard of oganesson is radiological rather than chemical. Known atoms decay by alpha emission and through radioactive daughter nuclei on extremely short timescales. Because only a few atoms are produced in shielded accelerator targets, ordinary chemical exposure is not a realistic scenario. Target materials and reaction products require standard controls for radioactive heavy-element experiments.
Oganesson has no confirmed natural occurrence and no known environmental cycle. Any atoms made in laboratories decay long before they could disperse as a chemical contaminant. Environmental considerations are therefore associated with accelerator operations, irradiated targets, and radioactive residues, not with persistent oganesson itself.
Oganesson has no commodity market, no industrial supply chain, and no recoverable stock. It is produced only in specialized nuclear laboratories by bombarding rare actinide targets, notably californium-249 (²⁴⁹Cf), with calcium-48 (⁴⁸Ca) ions. Production depends on scarce target isotopes, long accelerator runs, and detection of individual decay chains. Substitution and recycling are not meaningful concepts for the element itself.
Made by bombarding californium-249 with calcium-48.
Oganesson is not expected to be a persistent cosmic element because its known nuclei are far too unstable. Superheavy nuclei may be formed transiently in extreme nucleosynthetic environments, but no natural or extraterrestrial oganesson has been confirmed. Its relevance to astrophysics is mainly through theoretical work on nuclear stability at very high atomic number.
- Oganesson is the heaviest element with an officially approved name.
- Its placement under radon does not mean its chemistry is known to resemble radon closely.
- The name honors nuclear physicist Yuri Oganessian.
- Individual oganesson atoms are identified through correlated decay chains, not by weighing or isolating the element.
- Relativistic effects are expected to be central to any real oganesson chemistry.
画像
性質
物理的性質
- 密度
- 7000 kg/m³ 全元素の密度を比較 →
- 標準温度・圧力（STP）での相
- 気体 全元素の標準温度・圧力（STP）での相を比較 →
- 沸点
- -243.15 °C 全元素の沸点を比較 →
化学的性質
- 電子親和力
- 0.056 eV
- 酸化数
- −1, 0, +1, +2, +4, +6 全元素の酸化数を比較 →
- 価電子
- 8 全元素の価電子を比較 →
- 電子配置
- [Rn] 7s2 7p6 5f14 6d10 (予測値)
熱力学的性質
データなし
原子核
- 陽子数
- 118 全元素の陽子数を比較 →
- 中性子数
- 175 全元素の中性子数を比較 →
- 既知の同位体
- 2 全元素の既知の同位体を比較 →
- 安定同位体
- 0 全元素の安定同位体を比較 →
- 質量数（最も安定な同位体）
- 294
- 最も安定な同位体
- Og-293
- 発見年
- 2006
存在度
データなし
結晶構造
データなし
電子構造
- 各電子殻の電子数
- 14, 10, 8 全元素の各電子殻の電子数を比較 →
識別子
- CAS登録番号
- 54144-19-3 全元素のCAS登録番号を比較 →
- InChI
- InChI=1S/Og
- InChI Key
- GOANEQIZDYDFCO-UHFFFAOYSA-N
電子配置 予測値
——このイオンの電子配置データはありません。
原子モデル
同位体によって中性子数、質量、安定性は変わりますが、中性原子の電子配置は変わりません。
データなし
模式的な原子モデルです。実際の縮尺とは異なります。
原子の指紋
発光／吸収スペクトル
同位体分布
安定同位体はありません。
| 質量数 | 原子質量（u） | 天然存在比 | 半減期 |
|---|---|---|---|
| 293 放射性 | 293.21356 ± 0.00078 | データなし | 1 ms |
| 294 放射性 | 294.21392 ± 0.00071 | データなし | 0.7 ms |
相／状態
理由: 沸点（-243.15 °C）より268.1 °C高い
模式図、実際の縮尺とは異なります
相転移点
密度
標準条件下
現在の温度Tにおいて理想気体の状態方程式で推定
固相の結晶構造データはありません
同位体 (2)
| 質量数 | 原子質量（u） | 天然存在比 | 半減期 | 崩壊形式 | |
|---|---|---|---|---|---|
| 293 放射性 | 293.21356 ± 0.00078 | データなし | 1 ms | α ? | |
| 294 放射性 | 294.21392 ± 0.00071 | データなし | 0.7 ms | α ≈100%SF ? |
詳細な性質
共有結合半径（詳細）
- 共有結合半径（Pyykkö）
- 157 pm
番号付けの尺度
- Mendeleev
- 118
分極率と分散
- 双極子分極率
- 58 a.u.
- 双極子分極率（不確かさ）
- 6 a.u.
希ガスの性質
酸化数の分類
専門参考データ
同位体の崩壊形式 (3)
| 同位体 | モード | 強度 |
|---|---|---|
| 293 | A | — |
| 294 | A | 100% |
| 294 | SF | — |
追加データ
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
Not Applicable
参考文献 (1)
- [5] Oganesson https://education.jlab.org/itselemental/ele118.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
Not Applicable
参考文献 (1)
- [5] Oganesson https://education.jlab.org/itselemental/ele118.html
参考文献
(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 Oganesson.