Bohrium (Bh)
transition-metalSolid
मानक परमाणु भार
[270]इलेक्ट्रॉन विन्यास
[Rn] 7s2 5f14 6d5गलनांक
उपलब्ध नहींक्वथनांक
उपलब्ध नहींघनत्व
3.71e+4 kg/m³ऑक्सीकरण अवस्थाएँ
+3, +4, +5, +7विद्युतऋणात्मकता (पॉलिंग)
उपलब्ध नहींआयनन ऊर्जा (प्रथम)
7.7 eVखोज का वर्ष
1976परमाणु त्रिज्या
128 pmविवरण
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.
चित्र
गुण
भौतिक
- परमाणु त्रिज्या (आनुभविक)
- 128 pm सभी तत्वों की परमाणु त्रिज्या (आनुभविक) की तुलना करें →
- घनत्व
- 3.71 × 104 kg/m³ सभी तत्वों की घनत्व की तुलना करें →
रासायनिक
- इलेक्ट्रॉन बंधुता
- 0.44 eV
- आयनन ऊर्जा (प्रथम)
- 7.7 eV सभी तत्वों की आयनन ऊर्जा (प्रथम) की तुलना करें →
- आयनन ऊर्जा (द्वितीय)
- 17.50006 eV सभी तत्वों की आयनन ऊर्जा (द्वितीय) की तुलना करें →
- आयनन ऊर्जा (तृतीय)
- 26.700092 eV सभी तत्वों की आयनन ऊर्जा (तृतीय) की तुलना करें →
- आयनन ऊर्जा (चतुर्थ)
- 37.300128 eV सभी तत्वों की आयनन ऊर्जा (चतुर्थ) की तुलना करें →
- आयनन ऊर्जा (पंचम)
- 49.000169 eV सभी तत्वों की आयनन ऊर्जा (पंचम) की तुलना करें →
- ऑक्सीकरण अवस्थाएँ
- +3, +4, +5, +7 सभी तत्वों की ऑक्सीकरण अवस्थाएँ की तुलना करें →
- संयोजकता इलेक्ट्रॉन
- 7 सभी तत्वों की संयोजकता इलेक्ट्रॉन की तुलना करें →
- इलेक्ट्रॉन विन्यास
- [Rn] 7s2 5f14 6d5
ऊष्मागतिक
उपलब्ध नहीं
नाभिकीय
- प्रोटॉन
- 107 सभी तत्वों की प्रोटॉन की तुलना करें →
- न्यूट्रॉन
- 163 सभी तत्वों की न्यूट्रॉन की तुलना करें →
- ज्ञात समस्थानिक
- 19 सभी तत्वों की ज्ञात समस्थानिक की तुलना करें →
- स्थिर समस्थानिक
- 0 सभी तत्वों की स्थिर समस्थानिक की तुलना करें →
- द्रव्यमान संख्या (सबसे स्थिर)
- 270
- सबसे स्थिर समस्थानिक
- Bh-270
- खोज का वर्ष
- 1976
प्रचुरता
उपलब्ध नहीं
क्रिस्टल संरचना
उपलब्ध नहीं
इलेक्ट्रॉनिक संरचना
- प्रति कोश इलेक्ट्रॉन
- 2, 8, 18, 32, 32, 13, 2 सभी तत्वों की प्रति कोश इलेक्ट्रॉन की तुलना करें →
पहचानकर्ता
- CAS संख्या
- 54037-14-8 सभी तत्वों की CAS संख्या की तुलना करें →
- टर्म प्रतीक
- 5/2
- InChI
- InChI=1S/Bh
- InChI कुंजी
- INOXRQQPOOCQPH-UHFFFAOYSA-N
इलेक्ट्रॉन विन्यास पूर्वानुमानित
Bh: 5f¹⁴ 6d⁵ 7s²[Rn] 5f¹⁴ 6d⁵ 7s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁶ 5f¹⁴ 6d⁵ 7s²परमाणु मॉडल
समस्थानिक न्यूट्रॉन की संख्या, द्रव्यमान और स्थिरता बदलते हैं — उदासीन परमाणु का इलेक्ट्रॉन विन्यास नहीं।
सांकेतिक परमाणु मॉडल, वास्तविक अनुपात में नहीं।
परमाणु पहचान-चिह्न
उत्सर्जन / अवशोषण स्पेक्ट्रम
समस्थानिक वितरण
कोई स्थिर समस्थानिक नहीं है।
| द्रव्यमान संख्या | परमाणु द्रव्यमान (u) | प्राकृतिक प्रचुरता | अर्धायु |
|---|---|---|---|
| 263 रेडियोधर्मी | 263.12292 ± 0.00033 | उपलब्ध नहीं | 200 ms |
| 268 रेडियोधर्मी | 268.12969 ± 0.00041 | उपलब्ध नहीं | 190 सेकंड |
| 262 रेडियोधर्मी | 262.12297 ± 0.00033 | उपलब्ध नहीं | 84 ms |
| 276 रेडियोधर्मी | 276.149169 ± 0.000644 | उपलब्ध नहीं | 60 सेकंड |
| 274 रेडियोधर्मी | 274.14355 ± 0.00065 | उपलब्ध नहीं | 57 सेकंड |
प्रावस्था / अवस्था
प्रावस्था/अवस्था का डेटा उपलब्ध नहीं है
परमाणु स्पेक्ट्रम
96 में से 10 दिखाए जा रहे हैं। आयन के आवेश के अनुसार आरोही क्रम में व्यवस्थित।
उपलब्ध ऊर्जा स्तर डेटा ?
| आयन | आवेश | स्तर |
|---|---|---|
| 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 |
प्रावस्था/अवस्था का डेटा उपलब्ध नहीं है
यौगिक
समस्थानिक (5)
| द्रव्यमान संख्या | परमाणु द्रव्यमान (u) | प्राकृतिक प्रचुरता | अर्धायु | क्षय का प्रकार | |
|---|---|---|---|---|---|
| 263 रेडियोधर्मी | 263.12292 ± 0.00033 | उपलब्ध नहीं | 200 ms | α ? | |
| 268 रेडियोधर्मी | 268.12969 ± 0.00041 | उपलब्ध नहीं | 190 सेकंड | α ?SF ? | |
| 262 रेडियोधर्मी | 262.12297 ± 0.00033 | उपलब्ध नहीं | 84 ms | α ≈100%SF<20% | |
| 276 रेडियोधर्मी | 276.149169 ± 0.000644 | उपलब्ध नहीं | 60 सेकंड | α ?SF ? | |
| 274 रेडियोधर्मी | 274.14355 ± 0.00065 | उपलब्ध नहीं | 57 सेकंड | α =100% |
विस्तृत गुण
सहसंयोजक त्रिज्याएँ (विस्तृत)
- सहसंयोजक त्रिज्या (प्यूक्को)
- 141 pm
- सहसंयोजक त्रिज्या (प्यूक्को, द्विबंध)
- 128 pm
- सहसंयोजक त्रिज्या (प्यूक्को, त्रिबंध)
- 119 pm
संख्यांकन मापक्रम
- Mendeleev
- 58
ध्रुवणीयता और परिक्षेपण
- द्विध्रुव ध्रुवणीयता
- 38 a.u.
- द्विध्रुव ध्रुवणीयता (अनिश्चितता)
- 4 a.u.
ऑक्सीकरण अवस्था की श्रेणियाँ
उन्नत संदर्भ डेटा
समस्थानिक क्षय के 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 डेटा
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.
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. 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.