Bromine (Br)
halogenLiquid
标准原子量
79.904 u [79.901, 79.907]电子排布
[Ar] 4s2 3d10 4p5熔点
-7.2 °C沸点
58.8 °C密度
3102.8 kg/m³氧化态
−1, +1, +2, +3, +4, +5, +7电负性（鲍林）
2.96第一电离能
11.81381 eV发现年份
1825原子半径
115 pm详细信息
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.
图片
性质
物理性质
- 原子半径（经验值）
- 115 pm 比较所有元素的原子半径（经验值） →
- 共价半径
- 120 pm 比较所有元素的共价半径 →
- 范德华半径
- 183 pm 比较所有元素的范德华半径 →
- 密度
- 3102.8 kg/m³ 比较所有元素的密度 →
- 摩尔体积
- 0.0235 L/mol
- 标准温度和压力下的物相
- 液态 比较所有元素的标准温度和压力下的物相 →
- 熔点
- -7.2 °C 比较所有元素的熔点 →
- 沸点
- 58.8 °C 比较所有元素的沸点 →
- 热导率
- 0.005 W/(m·K) 比较所有元素的热导率 →
- 比热容
- 0.474 J/(g·K) 比较所有元素的比热容 →
- 摩尔热容
- 75.69 J/(mol·K) 比较所有元素的摩尔热容 →
- 晶体结构
- 正交 比较所有元素的晶体结构 →
化学性质
- 电负性（鲍林）
- 2.96 比较所有元素的电负性（鲍林） →
- 电负性（Allen）
- 2.685
- 电子亲和能
- 3.3635 eV
- 第一电离能
- 11.81381 eV 比较所有元素的第一电离能 →
- 第二电离能
- 21.591074 eV 比较所有元素的第二电离能 →
- 第三电离能
- 34.87112 eV 比较所有元素的第三电离能 →
- 第四电离能
- 47.782164 eV 比较所有元素的第四电离能 →
- 第五电离能
- 59.595205 eV 比较所有元素的第五电离能 →
- 氧化态
- −1, +1, +2, +3, +4, +5, +7 比较所有元素的氧化态 →
- 价电子
- 7 比较所有元素的价电子 →
- 电子排布
- [Ar] 4s2 3d10 4p5
热力学性质
- 三相点（温度）
- -7.25 °C
- 三相点（压力）
- 5879 Pa
- 临界点（温度）
- 315 °C
- 临界点（压力）
- 1.034e+7 Pa
- 熔化热
- 0.10955071 eV 比较所有元素的熔化热 →
- 汽化热
- 0.31051459 eV 比较所有元素的汽化热 →
- 原子化热
- 1.159766 eV
- 原子化焓
- 1.159248 eV
核性质
- 质子
- 35 比较所有元素的质子 →
- 中子
- 44 比较所有元素的中子 →
- 已知同位素
- 34 比较所有元素的已知同位素 →
- 稳定同位素
- 2 比较所有元素的稳定同位素 →
- 最稳定同位素
- Br-79
- 发现年份
- 1825
丰度
- 丰度（地壳）
- 2.4 mg/kg 比较所有元素的丰度（地壳） →
- 丰度（海洋）
- 67.3 mg/L 比较所有元素的丰度（海洋） →
晶体结构
- 晶格常数a
- 667 pm
电子结构
- 各电子层电子数
- 2, 8, 18, 7 比较所有元素的各电子层电子数 →
标识符
- CAS登记号
- 7726-95-6 比较所有元素的CAS登记号 →
- 谱项符号
- 2P°3/2
- InChI
- InChI=1S/Br
- InChI Key
- WKBOTKDWSSQWDR-UHFFFAOYSA-N
电子排布 实测值
Br: 3d¹⁰ 4s² 4p⁵[Ar] 3d¹⁰ 4s² 4p⁵1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁵原子模型
不同同位素的中子数、质量和稳定性不同，但中性原子的电子排布不变。
原子模型示意图，未按比例绘制。
原子指纹
发射 / 吸收光谱
同位素分布
| 质量数 | 原子质量（u） | 天然丰度 | 半衰期 |
|---|---|---|---|
| 79 稳定 | 78.9183376 ± 0.0000014 | 50.6900% | 稳定 |
| 81 稳定 | 80.9162897 ± 0.0000014 | 49.3100% | 稳定 |
物相 / 状态
原因: 位于熔点（-7.2 °C）与沸点（58.8 °C）之间
示意图，未按比例绘制
相变点
相变能
在熔点熔化1 mol物质所需的能量
在沸点汽化1 mol物质所需的能量
密度
标准条件下
暂无液相数据
高级
原子光谱
已显示10项，共35项。 按离子电荷升序排列。
收录谱线 ?
| 离子 | 电荷 | 谱线总数 | 跃迁概率 | 能级标记 |
|---|---|---|---|---|
| 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 |
收录能级 ?
| 离子 | 电荷 | 能级 |
|---|---|---|
| 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 |
离子半径
| 电荷 | 配位 | 自旋 | 半径 |
|---|---|---|---|
| -1 | 6 | 暂无 | 196 pm |
| +3 | 4 | 暂无 | 59 pm |
| +5 | 3 | 暂无 | 31 pm |
| +7 | 4 | 暂无 | 25 pm |
| +7 | 6 | 暂无 | 39 pm |
化合物
同位素 (2)
| 质量数 | 原子质量（u） | 天然丰度 | 半衰期 | 衰变方式 | |
|---|---|---|---|---|---|
| 79 稳定 | 78.9183376 ± 0.0000014 | 50.6900% ± 0.0700% | 稳定 | stable | |
| 81 稳定 | 80.9162897 ± 0.0000014 | 49.3100% ± 0.0700% | 稳定 | stable |
扩展性质
共价半径（扩展）
- 共价半径（Pyykkö）
- 114 pm
- 共价半径（Pyykkö，双键）
- 109 pm
- 共价半径（Pyykkö，三键）
- 110 pm
- 共价半径（Bragg）
- 119 pm
范德华半径
- Bondi
- 183 pm
- Batsanov
- 190 pm
- Alvarez
- 186 pm
- UFF
- 418.9 pm
- MM3
- 222 pm
- Dreiding
- 395 pm
- Rowland–Taylor
- 187 pm
原子半径与金属半径
- 原子半径（Rahm）
- 219 pm
- 金属半径（C12）
- 117 pm
编号标度
- Mendeleev
- 108
- Pettifor
- 98
- Glawe
- 100
电负性标度
- Ghosh
- 0
- Gunnarsson–Lundqvist
- 8
- Robles–Bartolotti
- 7
极化率与色散
- 偶极极化率
- 21 a.u.
- 偶极极化率（不确定度）
- 1 a.u.
- C₆
- 162 Ha·Bohr6
- C₆ (Gould–Bučko)
- 187 Ha·Bohr6
化学亲和力
- 质子亲和能
- 554.4 kJ/mol
- 气相碱性
- 531.2 kJ/mol
供应风险与经济性
- 生产集中度
- 44
- 相对供应风险
- 7
- 储量分布
- 64
- 政治稳定性（最大生产国）
- 57
- 政治稳定性（最大储量国）
- 57
相变与同素异形体
| 熔点 | 265.95 K |
| 沸点 | 331.95 K |
| 临界点（温度） | 588.15 K |
| 临界点（压力） | 10.34 MPa |
| 三相点（温度） | 265.9 K |
| 三相点（压力） | 5.88 kPa |
氧化态分类
高级参考数据
屏蔽常数 (8)
| n | 轨道 | 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 |
晶体半径详情 (5)
| 电荷 | CN | 自旋 | rcrystal (pm) | 来源 |
|---|---|---|---|---|
| -1 | VI | 182 | Pauling's (1960) crystal radius, | |
| 3 | IVSQ | 73 | ||
| 5 | IIIPY | 45 | ||
| 7 | IV | 39 | ||
| 7 | VI | 53 | Ahrens (1952) ionic radius, |
同位素衰变方式 (54)
| 同位素 | 模式 | 强度 |
|---|---|---|
| 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射线散射因子 (506)
| 能量 (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 |
补充数据
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.