Bohrium (Bh)
transition-metalSolid
प्रमाणित अणुभार
[270]इलेक्ट्रॉन संरूपण
[Rn] 7s2 5f14 6d5द्रवणांक
उपलब्ध नाहीउत्कलनांक
उपलब्ध नाहीघनता
3.71e+4 kg/m³ऑक्सिडीकरण अवस्था
+3, +4, +5, +7विद्युतऋणता (पॉलिंग)
उपलब्ध नाहीआयनीकरण ऊर्जा (पहिली)
7.7 eVशोधाचे वर्ष
1976अणुत्रिज्या
128 pmतपशील
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.
No macroscopic sample of bohrium has been prepared, so its visible appearance is unknown. It is expected from periodic trends and calculations to be a dense metallic solid under ordinary conditions, but this has not been directly observed.
Bohrium has no practical use outside scientific research. Its isotopes are used as subjects in nuclear-structure studies, decay-chain assignments, and tests of models for superheavy-element stability. Chemical experiments with individual atoms have also used bohrium to examine whether group trends continue into the 6d transition series. The element is not available for devices, materials, medicine, or industrial chemistry.
Since only a few atoms of bohrium have ever been made, there are currently no uses for bohrium outside of basic scientific research.
No weighable bohrium compound has been isolated. The best established chemical evidence concerns bohrium in the +7 oxidation state, especially a volatile oxychloride assigned as bohrium oxychloride, BhO₃Cl, formed and transported in gas-phase atom-at-a-time experiments. Its behavior resembles that of rhenium oxychloride, ReO₃Cl, supporting placement in group 7. Other oxidation states and compounds, including oxides and halides, are predicted by analogy and relativistic calculations but remain poorly characterized experimentally.
See more information at the Bohrium compound page.
Bohrium isotopes are radioactive and decay by alpha emission or spontaneous fission, depending on the isotope. Because only a few atoms are produced, chemical toxicity has not been measured and is not a practical exposure issue outside specialized laboratories. The main hazards in production experiments are ionizing radiation, activated targets and equipment, and decay products handled under accelerator radiological controls.
Bohrium has no known natural occurrence and no environmental cycle. Any atom released from an experiment would decay rapidly to other nuclides, so persistence, transport, and bioaccumulation of elemental bohrium have not been observed. Its environmental relevance is therefore limited to controlled research facilities and the management of radioactive activation products from those facilities.
Bohrium has no commodity market, commercial supply chain, or recoverable inventory. It is produced in accelerator experiments by fusing heavy target nuclei with ion beams, for example in reactions involving bismuth or actinide targets, or it appears in decay chains of heavier synthetic elements. Production yields are at the level of individual atoms, and separation is performed only for immediate detection or chemical study. Economic considerations are those of superheavy-element research infrastructure rather than material demand, substitution, or recycling.
Obtained by bombarding bismuth-204 with chromium-54.
Bohrium is not expected to survive as a primordial element because all known and predicted accessible isotopes are far too short-lived on geological or cosmic timescales. Superheavy nuclei near bohrium could be formed transiently in extreme neutron-rich nucleosynthesis, but no extraterrestrial bohrium has been detected. Claims about longer-lived superheavy nuclei remain theoretical for this element.
- Bohrium is named for Niels Bohr, with the spelling chosen to fit the usual element-name ending.
- The accepted symbol is Bh; the temporary systematic name was unniseptium.
- Unambiguous identification relies on correlated decay chains, not on collecting visible material.
- Atom-at-a-time chemistry showed bohrium behaves more like rhenium than like a chemically anomalous outlier.
- The first confirmed syntheses used cold-fusion heavy-ion reactions.
प्रतिमा
गुणधर्म
भौतिक
- अणुत्रिज्या (अनुभवाधारित)
- 128 pm सर्व घटकांच्या अणुत्रिज्या (अनुभवाधारित) ची तुलना करा →
- घनता
- 3.71 × 104 kg/m³ सर्व घटकांच्या घनता ची तुलना करा →
रासायनिक
- इलेक्ट्रॉन आसक्ती
- 0.44 eV
- आयनीकरण ऊर्जा (पहिली)
- 7.7 eV सर्व घटकांच्या आयनीकरण ऊर्जा (पहिली) ची तुलना करा →
- आयनीकरण ऊर्जा (दुसरी)
- 17.50006 eV सर्व घटकांच्या आयनीकरण ऊर्जा (दुसरी) ची तुलना करा →
- आयनीकरण ऊर्जा (तिसरी)
- 26.700092 eV सर्व घटकांच्या आयनीकरण ऊर्जा (तिसरी) ची तुलना करा →
- आयनीकरण ऊर्जा (चौथी)
- 37.300128 eV सर्व घटकांच्या आयनीकरण ऊर्जा (चौथी) ची तुलना करा →
- आयनीकरण ऊर्जा (पाचवी)
- 49.000169 eV सर्व घटकांच्या आयनीकरण ऊर्जा (पाचवी) ची तुलना करा →
- ऑक्सिडीकरण अवस्था
- +3, +4, +5, +7 सर्व घटकांच्या ऑक्सिडीकरण अवस्था ची तुलना करा →
- संयुजा इलेक्ट्रॉन
- 7 सर्व घटकांच्या संयुजा इलेक्ट्रॉन ची तुलना करा →
- इलेक्ट्रॉन संरूपण
- [Rn] 7s2 5f14 6d5
उष्मागतिक
उपलब्ध नाही
केंद्रकीय
- प्रोटॉन
- 107 सर्व घटकांच्या प्रोटॉन ची तुलना करा →
- न्यूट्रॉन
- 163 सर्व घटकांच्या न्यूट्रॉन ची तुलना करा →
- ज्ञात समस्थानिके
- 19 सर्व घटकांच्या ज्ञात समस्थानिके ची तुलना करा →
- स्थिर समस्थानिके
- 0 सर्व घटकांच्या स्थिर समस्थानिके ची तुलना करा →
- वस्तुमानांक (सर्वाधिक स्थिर)
- 270
- सर्वाधिक स्थिर समस्थानिक
- Bh-270
- शोधाचे वर्ष
- 1976
विपुलता
उपलब्ध नाही
स्फटिक संरचना
उपलब्ध नाही
इलेक्ट्रॉन संरचना
- प्रत्येक कवचातील इलेक्ट्रॉन
- 2, 8, 18, 32, 32, 13, 2 सर्व घटकांच्या प्रत्येक कवचातील इलेक्ट्रॉन ची तुलना करा →
ओळखचिन्हे
- CAS क्रमांक
- 54037-14-8 सर्व घटकांच्या CAS क्रमांक ची तुलना करा →
- टर्म चिन्ह
- 5/2
- InChI
- InChI=1S/Bh
- InChI की
- INOXRQQPOOCQPH-UHFFFAOYSA-N
इलेक्ट्रॉन संरूपण भाकीत केलेले
Bh: 5f¹⁴ 6d⁵ 7s²[Rn] 5f¹⁴ 6d⁵ 7s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁶ 5f¹⁴ 6d⁵ 7s²अणुप्रतिमान
समस्थानिकांमुळे न्यूट्रॉन संख्या, वस्तुमान आणि स्थैर्य बदलते — विद्युतदृष्ट्या उदासीन अणूचे इलेक्ट्रॉन संरूपण बदलत नाही.
योजनात्मक अणुप्रतिमान, प्रमाणानुसार नाही.
अणूची विशिष्ट ओळख
उत्सर्जन / शोषण वर्णपट
समस्थानिक वितरण
स्थिर समस्थानिके नाहीत.
| वस्तुमानांक | अणुवस्तुमान (u) | नैसर्गिक विपुलता | अर्धायुष्य |
|---|---|---|---|
| 263 किरणोत्सारी | २६३.१२२९२ ± ०.०००३३ | उपलब्ध नाही | 200 ms |
| 268 किरणोत्सारी | २६८.१२९६९ ± ०.०००४१ | उपलब्ध नाही | 190 सेकंद |
| 262 किरणोत्सारी | २६२.१२२९७ ± ०.०००३३ | उपलब्ध नाही | 84 ms |
| 276 किरणोत्सारी | २७६.१४९१६९ ± ०.०००६४४ | उपलब्ध नाही | 60 सेकंद |
| 274 किरणोत्सारी | २७४.१४३५५ ± ०.०००६५ | उपलब्ध नाही | 57 सेकंद |
अवस्था / स्थिती
अवस्थेविषयी माहिती उपलब्ध नाही
अणुवर्णपट
96 पैकी 10 दाखवले आहेत. आयनाच्या विद्युतभारानुसार चढत्या क्रमाने मांडलेले.
ऊर्जा पातळ्यांचा संग्रह ?
| आयन | विद्युतभार | पातळ्या |
|---|---|---|
| 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 |
अवस्थेविषयी माहिती उपलब्ध नाही
संयुगे
समस्थानिके (5)
| वस्तुमानांक | अणुवस्तुमान (u) | नैसर्गिक विपुलता | अर्धायुष्य | क्षय प्रकार | |
|---|---|---|---|---|---|
| 263 किरणोत्सारी | २६३.१२२९२ ± ०.०००३३ | उपलब्ध नाही | 200 ms | α ? | |
| 268 किरणोत्सारी | २६८.१२९६९ ± ०.०००४१ | उपलब्ध नाही | 190 सेकंद | α ?SF ? | |
| 262 किरणोत्सारी | २६२.१२२९७ ± ०.०००३३ | उपलब्ध नाही | 84 ms | α ≈100%SF<20% | |
| 276 किरणोत्सारी | २७६.१४९१६९ ± ०.०००६४४ | उपलब्ध नाही | 60 सेकंद | α ?SF ? | |
| 274 किरणोत्सारी | २७४.१४३५५ ± ०.०००६५ | उपलब्ध नाही | 57 सेकंद | α =100% |
विस्तारित गुणधर्म
सहसंयुजी त्रिज्या (विस्तारित)
- सहसंयुजी त्रिज्या (प्युक्को)
- 141 pm
- सहसंयुजी त्रिज्या (प्युक्को, दुहेरी बंध)
- 128 pm
- सहसंयुजी त्रिज्या (प्युक्को, तिहेरी बंध)
- 119 pm
क्रमांकन मापनपट्ट्या
- Mendeleev
- 58
ध्रुवणक्षमता आणि अपस्करण
- द्विध्रुव ध्रुवणक्षमता
- 38 a.u.
- द्विध्रुव ध्रुवणक्षमता (अनिश्चितता)
- 4 a.u.
ऑक्सिडीकरण अवस्थांचे वर्ग
प्रगत संदर्भ माहिती
समस्थानिक क्षय प्रकार (32)
| समस्थानिक | मोड | तीव्रता |
|---|---|---|
| 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% |
अतिरिक्त माहिती
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
Not Applicable
संदर्भ (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
Not Applicable
संदर्भ (1)
संदर्भ
(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.