Bromine (Br)
halogenLiquid
標準原子量
79.904 u [79.901, 79.907]電子配置
[Ar] 4s2 3d10 4p5融点
-7.2 °C沸点
58.8 °C密度
3102.8 kg/m³酸化数
−1, +1, +2, +3, +4, +5, +7電気陰性度（Pauling）
2.96第1イオン化エネルギー
11.81381 eV発見年
1825原子半径
115 pm詳細
Bromine is a halogen, group 17 element, and the only nonmetal that is liquid near room temperature. Elemental bromine occurs as diatomic Br₂ and is a dense, volatile, strongly oxidizing substance. In nature bromine is found mainly as bromide ions in seawater, salt lakes, and subsurface brines. Its chemistry is intermediate between chlorine and iodine, with important roles in flame retardants, drilling fluids, pharmaceuticals, and photographic chemistry.
Bromine is the only nonmetallic liquid element. It is a heavy, mobile, reddish-brown liquid, volatilizing readily at room temperature to a red vapor with a strong disagreeable odor, resembling chlorine, and having a very irritating effect on the eyes and throat; it is readily soluble in water or carbon disulfide, forming a red solution, is less active than chlorine but more so than iodine; it unites readily with many elements and has a bleaching action; when spilled on the skin it produces painful sores. It presents a serious health hazard, and maximum safety precautions should be taken when handling it.
The name derives from the Greek bromos for "bad stench" or "bad odour". It was first prepared by the German chemist Carl Löwig in 1825, but it was first publicly announced in 1826 by the French chemist and pharmacist Antoine-Jérôme Balard, and so the discovery is, therefore, credited to him.
The only nonmetallic element that is a liquid at normal room temperatures, bromine was produced by Carl Löwig, a young chemistry student, the summer before starting his freshman year at Heidelberg. When he showed his professor, Leopold Gmelin, the red, smelly liquid he had produced, Gmelin realized that this was an unknown substance and encouraged Löwig to produce more of it so they could study it in detail. Unfortunately, winter exams and the holidays delayed Löwig's work long enough for another chemist, Antoine-Jérôme Balard, to publish a paper in 1826 describing the new element. Balard was credited with the discovery and named it after the greek word for stench, bromos. Today, bromine is primarily obtained by treating brines from wells in Michigan and Arkansas with chlorine.
From the Greek word bromos, stench. Discovered by Balard in 1826, but not prepared in quantity until 1860.
Pure bromine is a dark red-brown, mobile liquid at ordinary conditions. It gives off a heavy red-brown vapor with a sharp, irritating odor. It freezes to a reddish solid and boils just above room temperature, so noticeable vapor is present from an open container.
Bromine compounds are used in flame retardants for plastics, textiles, and electronic materials, although some older persistent formulations have been restricted or replaced. Dense calcium bromide (CaBr₂), sodium bromide (NaBr), and zinc bromide (ZnBr₂) brines are used in oil and gas drilling and completion fluids. Silver bromide (AgBr) remains important in traditional photographic films and papers. Organobromine intermediates are also used in pharmaceuticals, agrochemicals, dyes, and specialty chemicals.
Elemental bromine is a hazardous material. It causes severe burns when it comes in contact with the skin and its vapor irritates the eyes, nose and throat. Most of the bromine produced in the United States was used in the manufacture of ethylene dibromide(C2H4Br2), a chemical added to leaded gasolines that prevented the accumulation of lead compounds within the engine. With the discontinuation of leaded gasolines in favor of unleaded gasolines, the demand for bromine has been greatly reduced. Silver bromide (AgBr), a chemical used in photography, now accounts for the largest use of bromine. Other bromine compounds are used in fumigants, in flameproofing agents and in some compounds used to purify water. Tyrian purple, an expensive purple dye known to ancient civilizations, was produced from an organic bromine compound secreted from a sea mussel known as the murex.
Bromine is used in making fumigants, flameproofing agents, water purification compounds, dyes, medicines, sanitizers, inorganic bromides for photography, etc. Organic bromides are also important.
Isotopes in Earth/Planetary Science
Molecules, atoms, and ions of the stable isotopes of bromine possess slightly different physical and chemical properties, and they commonly will be fractionated during physical, chemical, and biological processes, giving rise to variations in isotopic abundances and in atomic weights. There are substantial variations in the isotopic abundances of bromine in natural terrestrial materials (Fig. IUPAC.35.1). These variations are useful in investigating the origin of substances and studying environmental, hydrological, and geological processes [13] M. W. Wieser, T. B. Coplen. Pure Appl Chem.83, 359 (2011)., [278] R. L. Stotler, S. K. Frape, O. Shouakar-Stash. Chem. Geol.274, 38 (2010).. 79Br has been used as a groundwater tracer (Fig. IUPAC.35.2). Introduction of a solution spiked with 79Br to groundwater and measurement of the change in the isotope-amount ratio n(79Br)/n(81Br) over time has been used to monitor tracer breakthrough and to calculate bromide travel time [279] M. D’Alessandro, G. Bidoglio, F. Mousty, J. V. Sala Benito, A. Y. De Llano. J. Hydrol.193, 351 (1997)..
Isotopes in Medicine
77Br (with a half-life of 57 h) is used to label radiopharmaceuticals that bind to estrogen receptors for tumor imaging. 75Br (with a half-life of 97 min) is being used with positron emission tomography (PET) imaging [281] K. D. McElvany, J. A. Katzenellenbogen, K. E. Shafer, B. A. Siegel, S. G. Senderoff, M. J. Welch, Los Alamos Medical Radioisotope Group. J. Nucl. Med.23, 425 (1982)..
Isotopes Used as a Source of Radioactive Isotope(s)
79Br is used in the proton cyclotron to produce 77Kr, which decays to 77Br via the reaction 79Br (p, 3n) 77Kr, which decays into 77Br [282] E. Galiano, R. Tilbury. Appl. Radiat. Isot.49, 105 (1998)..
Bromine commonly forms bromide salts containing Br⁻, including sodium bromide (NaBr) and potassium bromide (KBr). It shows positive oxidation states in interhalogen and oxyanion chemistry, such as bromine chloride (BrCl), hypobromous acid (HOBr), bromate (BrO₃⁻), and perbromate (BrO₄⁻), though the higher oxidation states are less stable than comparable chlorine species. Hydrogen bromide (HBr) is a strong acid in water. Many organobromine compounds are useful synthetic intermediates because carbon-bromine bonds are reactive toward substitution and coupling reactions.
See more information at the Bromine compound page.
Elemental bromine (Br₂) is highly corrosive, toxic by inhalation, and a severe irritant to skin, eyes, and mucous membranes. Its vapor is hazardous even at low concentrations and reacts with many organic materials and reducing agents. Concentrated hydrobromic acid (HBr) is strongly acidic and corrosive. Some organobromine compounds are persistent, bioaccumulative, or toxic, but hazards vary widely with structure and exposure route.
Bromide is a natural constituent of seawater and evaporite brines, and it is cycled through oceans, salt deposits, aerosols, and biological processes. Marine organisms produce many organobromine compounds, some of which enter atmospheric chemistry. In water treatment, bromide can be oxidized to reactive bromine species and brominated disinfection by-products. Persistent brominated flame retardants can accumulate in sediments and biota, depending on their structure and use history.
Commercial bromine is produced mainly by oxidizing bromide-rich brines and stripping the liberated bromine from solution. Major feedstocks include highly saline inland brines, salt-lake brines, and some subsurface brines associated with mineral or hydrocarbon production. Demand is tied to flame retardants, drilling fluids, water-treatment chemicals, and specialty synthesis. Supply is geographically concentrated where suitable brines are available, and recycling is limited for many dispersive uses, although some brominated materials and process streams can be recovered or managed in closed systems.
A member of the halogen group, bromine is obtained from natural brines from wells in Michigan and Arkansas. Some bromine is extracted today from seawater, which contains only about 85 ppm.
Bromine is a relatively scarce element in the cosmos compared with lighter halogens. It is produced by neutron-capture processes in earlier generations of stars and is incorporated into dust, meteorites, and planetary materials in small amounts. On Earth and other volatile-bearing bodies, its geochemistry is controlled mainly by the soluble bromide ion, which concentrates in brines during evaporation.
- Bromine is one of only two elements that are liquid at standard laboratory temperatures; the other is mercury.
- Its name comes from a Greek word referring to stench, reflecting the odor of Br₂ vapor.
- Silver bromide darkens on exposure to light, a property central to photographic emulsions.
- Bromide ions are usually more concentrated in late-stage evaporite brines than in ordinary seawater.
- Elemental bromine is dense enough that many common solids float on it, but contact is dangerous.
画像
性質
物理的性質
- 原子半径（経験値）
- 115 pm 全元素の原子半径（経験値）を比較 →
- 共有結合半径
- 120 pm 全元素の共有結合半径を比較 →
- ファンデルワールス半径
- 183 pm 全元素のファンデルワールス半径を比較 →
- 密度
- 3102.8 kg/m³ 全元素の密度を比較 →
- モル体積
- 0.0235 L/mol
- 標準温度・圧力（STP）での相
- 液体 全元素の標準温度・圧力（STP）での相を比較 →
- 融点
- -7.2 °C 全元素の融点を比較 →
- 沸点
- 58.8 °C 全元素の沸点を比較 →
- 熱伝導率
- 0.005 W/(m·K) 全元素の熱伝導率を比較 →
- 比熱容量
- 0.474 J/(g·K) 全元素の比熱容量を比較 →
- モル熱容量
- 75.69 J/(mol·K) 全元素のモル熱容量を比較 →
- 結晶構造
- 斜方晶系 全元素の結晶構造を比較 →
化学的性質
- 電気陰性度（Pauling）
- 2.96 全元素の電気陰性度（Pauling）を比較 →
- 電気陰性度（Allen）
- 2.685
- 電子親和力
- 3.3635 eV
- 第1イオン化エネルギー
- 11.81381 eV 全元素の第1イオン化エネルギーを比較 →
- 第2イオン化エネルギー
- 21.591074 eV 全元素の第2イオン化エネルギーを比較 →
- 第3イオン化エネルギー
- 34.87112 eV 全元素の第3イオン化エネルギーを比較 →
- 第4イオン化エネルギー
- 47.782164 eV 全元素の第4イオン化エネルギーを比較 →
- 第5イオン化エネルギー
- 59.595205 eV 全元素の第5イオン化エネルギーを比較 →
- 酸化数
- −1, +1, +2, +3, +4, +5, +7 全元素の酸化数を比較 →
- 価電子
- 7 全元素の価電子を比較 →
- 電子配置
- [Ar] 4s2 3d10 4p5
熱力学的性質
- 三重点（温度）
- -7.25 °C
- 三重点（圧力）
- 5879 Pa
- 臨界点（温度）
- 315 °C
- 臨界点（圧力）
- 1.034e+7 Pa
- 融解熱
- 0.10955071 eV 全元素の融解熱を比較 →
- 蒸発熱
- 0.31051459 eV 全元素の蒸発熱を比較 →
- 原子化熱
- 1.159766 eV
- 原子化エンタルピー
- 1.159248 eV
原子核
- 陽子数
- 35 全元素の陽子数を比較 →
- 中性子数
- 44 全元素の中性子数を比較 →
- 既知の同位体
- 34 全元素の既知の同位体を比較 →
- 安定同位体
- 2 全元素の安定同位体を比較 →
- 最も安定な同位体
- Br-79
- 発見年
- 1825
存在度
- 存在度（地殻）
- 2.4 mg/kg 全元素の存在度（地殻）を比較 →
- 存在度（海洋）
- 67.3 mg/L 全元素の存在度（海洋）を比較 →
結晶構造
- 格子定数a
- 667 pm
電子構造
- 各電子殻の電子数
- 2, 8, 18, 7 全元素の各電子殻の電子数を比較 →
識別子
- CAS登録番号
- 7726-95-6 全元素のCAS登録番号を比較 →
- 項記号
- 2P°3/2
- InChI
- InChI=1S/Br
- InChI Key
- WKBOTKDWSSQWDR-UHFFFAOYSA-N
電子配置 測定値
Br: 3d¹⁰ 4s² 4p⁵[Ar] 3d¹⁰ 4s² 4p⁵1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁵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。
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
| 質量数 | 原子質量（u） | 天然存在比 | 半減期 |
|---|---|---|---|
| 79 安定 | 78.9183376 ± 0.0000014 | 50.6900% | 安定 |
| 81 安定 | 80.9162897 ± 0.0000014 | 49.3100% | 安定 |
相／状態
理由: 融点（-7.2 °C）と沸点（58.8 °C）の間
模式図、実際の縮尺とは異なります
相転移点
相転移エネルギー
融点で1 molを融解させるのに必要なエネルギー
沸点で1 molを蒸発させるのに必要なエネルギー
密度
標準条件下
液相のデータはありません
詳細
原子スペクトル
全35件中10件を表示しています。 イオンの電荷の昇順で並べています。
スペクトル線データの収録状況 ?
| イオン | 電荷 | スペクトル線の総数 | 遷移確率 | 準位の表記 |
|---|---|---|---|---|
| Br I | 0 | 170 | 54 | 170 |
| Br II | +1 | 118 | 3 | 0 |
| Br III | +2 | 75 | 0 | 0 |
| Br IV | +3 | 136 | 0 | 136 |
| Br V | +4 | 22 | 0 | 0 |
準位データの収録状況 ?
| イオン | 電荷 | 準位 |
|---|---|---|
| Br I | 0 | 265 |
| Br II | +1 | 132 |
| Br III | +2 | 53 |
| Br IV | +3 | 43 |
| Br V | +4 | 10 |
| Br VI | +5 | 12 |
| Br VII | +6 | 6 |
| Br VIII | +7 | 12 |
| Br IX | +8 | 5 |
| Br X | +9 | 2 |
イオン半径
| 電荷 | 配位 | スピン | 半径 |
|---|---|---|---|
| -1 | 6 | データなし | 196 pm |
| +3 | 4 | データなし | 59 pm |
| +5 | 3 | データなし | 31 pm |
| +7 | 4 | データなし | 25 pm |
| +7 | 6 | データなし | 39 pm |
化合物
同位体 (2)
| 質量数 | 原子質量（u） | 天然存在比 | 半減期 | 崩壊形式 | |
|---|---|---|---|---|---|
| 79 安定 | 78.9183376 ± 0.0000014 | 50.6900% ± 0.0700% | 安定 | stable | |
| 81 安定 | 80.9162897 ± 0.0000014 | 49.3100% ± 0.0700% | 安定 | stable |
詳細な性質
共有結合半径（詳細）
- 共有結合半径（Pyykkö）
- 114 pm
- 共有結合半径（Pyykkö、二重結合）
- 109 pm
- 共有結合半径（Pyykkö、三重結合）
- 110 pm
- 共有結合半径（Bragg）
- 119 pm
ファンデルワールス半径
- Bondi
- 183 pm
- Batsanov
- 190 pm
- Alvarez
- 186 pm
- UFF
- 418.9 pm
- MM3
- 222 pm
- Dreiding
- 395 pm
- Rowland–Taylor
- 187 pm
原子半径と金属半径
- 原子半径（Rahm）
- 219 pm
- 金属半径（C12）
- 117 pm
番号付けの尺度
- Mendeleev
- 108
- Pettifor
- 98
- Glawe
- 100
電気陰性度の尺度
- Ghosh
- 0
- Gunnarsson–Lundqvist
- 8
- Robles–Bartolotti
- 7
分極率と分散
- 双極子分極率
- 21 a.u.
- 双極子分極率（不確かさ）
- 1 a.u.
- C₆
- 162 Ha·Bohr6
- C₆ (Gould–Bučko)
- 187 Ha·Bohr6
化学親和力
- プロトン親和力
- 554.4 kJ/mol
- 気相塩基性
- 531.2 kJ/mol
供給リスクと経済性
- 生産集中度
- 44
- 相対供給リスク
- 7
- 埋蔵量の分布
- 64
- 政治的安定性（最大生産国）
- 57
- 政治的安定性（最大埋蔵国）
- 57
相転移と同素体
| 融点 | 265.95 K |
| 沸点 | 331.95 K |
| 臨界点（温度） | 588.15 K |
| 臨界点（圧力） | 10.34 MPa |
| 三重点（温度） | 265.9 K |
| 三重点（圧力） | 5.88 kPa |
酸化数の分類
専門参考データ
遮蔽定数 (8)
| n | 軌道 | σ |
|---|---|---|
| 1 | s | 0.7529 |
| 2 | p | 3.9436 |
| 2 | s | 9.3566 |
| 3 | d | 15.4409 |
| 3 | p | 15.4292 |
| 3 | s | 14.7815 |
| 4 | p | 25.972 |
| 4 | s | 24.4472 |
結晶半径の詳細 (5)
| 電荷 | CN | スピン | rcrystal (pm) | 由来 |
|---|---|---|---|---|
| -1 | VI | 182 | Pauling's (1960) crystal radius, | |
| 3 | IVSQ | 73 | ||
| 5 | IIIPY | 45 | ||
| 7 | IV | 39 | ||
| 7 | VI | 53 | Ahrens (1952) ionic radius, |
同位体の崩壊形式 (54)
| 同位体 | モード | 強度 |
|---|---|---|
| 65 | p | — |
| 66 | p | — |
| 67 | p | — |
| 68 | p | — |
| 69 | p | 100% |
| 70 | B+ | 100% |
| 70 | B+p | — |
| 71 | B+ | 100% |
| 72 | B+ | 100% |
| 73 | B+ | 100% |
X線散乱因子 (506)
| エネルギー (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 5.16199 |
| 10.1617 | — | 5.31855 |
| 10.3261 | — | 5.47986 |
| 10.4931 | — | 5.64606 |
| 10.6628 | — | 5.8173 |
| 10.8353 | — | 5.99373 |
| 11.0106 | — | 6.17552 |
| 11.1886 | — | 6.36281 |
| 11.3696 | — | 6.5558 |
| 11.5535 | — | 6.75463 |
追加データ
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
2.4 milligrams per kilogram
参考文献 (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
6.73×101 milligrams per liter
参考文献 (1)
Sources
Sources of this element.
A member of the halogen group, bromine is obtained from natural brines from wells in Michigan and Arkansas. Some bromine is extracted today from seawater, which contains only about 85 ppm.
参考文献 (1)
- [6] Bromine https://periodic.lanl.gov/35.shtml
Production
Production of this element (from raw materials or other compounds containing the element).
Much of the bromine output in the U.S. was used in the production of ethylene dibromide, a lead scavenger used in making gasoline anti-knock compounds. Lead in gasoline, however, has been drastically reduced due to environmental considerations. This will greatly affect future production of bromine.
参考文献 (1)
- [6] Bromine https://periodic.lanl.gov/35.shtml
参考文献
(9)
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 Bromine.
The element property data was retrieved from publications.