Bromine (Br)
halogenLiquid
Peso atômico padrão
79,904 u [79,901, 79,907]Configuração eletrônica
[Ar] 4s2 3d10 4p5Ponto de fusão
-7,2 °CPonto de ebulição
58,8 °CDensidade
3102,8 kg/m³Estados de oxidação
−1, +1, +2, +3, +4, +5, +7Eletronegatividade (Pauling)
2,96Energia de ionização (1ª)
11,81381 eVAno da descoberta
1825Raio atômico
115 pmDetalhes
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.
Imagens
Propriedades
Física
- Raio atômico (empírico)
- 115 pm Comparar Raio atômico (empírico) de todos os elementos →
- Raio covalente
- 120 pm Comparar Raio covalente de todos os elementos →
- Raio de van der Waals
- 183 pm Comparar Raio de van der Waals de todos os elementos →
- Densidade
- 3102,8 kg/m³ Comparar Densidade de todos os elementos →
- Volume molar
- 0,0235 L/mol
- Fase nas CNTP
- Líquido Comparar Fase nas CNTP de todos os elementos →
- Ponto de fusão
- -7,2 °C Comparar Ponto de fusão de todos os elementos →
- Ponto de ebulição
- 58,8 °C Comparar Ponto de ebulição de todos os elementos →
- Condutividade térmica
- 0,005 W/(m·K) Comparar Condutividade térmica de todos os elementos →
- Capacidade calorífica específica
- 0,474 J/(g·K) Comparar Capacidade calorífica específica de todos os elementos →
- Capacidade calorífica molar
- 75,69 J/(mol·K) Comparar Capacidade calorífica molar de todos os elementos →
- Estrutura cristalina
- Ortorrômbica Comparar Estrutura cristalina de todos os elementos →
Química
- Eletronegatividade (Pauling)
- 2,96 Comparar Eletronegatividade (Pauling) de todos os elementos →
- Eletronegatividade (Allen)
- 2,685
- Afinidade eletrônica
- 3,3635 eV
- Energia de ionização (1ª)
- 11,81381 eV Comparar Energia de ionização (1ª) de todos os elementos →
- Energia de ionização (2ª)
- 21,591074 eV Comparar Energia de ionização (2ª) de todos os elementos →
- Energia de ionização (3ª)
- 34,87112 eV Comparar Energia de ionização (3ª) de todos os elementos →
- Energia de ionização (4ª)
- 47,782164 eV Comparar Energia de ionização (4ª) de todos os elementos →
- Energia de ionização (5ª)
- 59,595205 eV Comparar Energia de ionização (5ª) de todos os elementos →
- Estados de oxidação
- −1, +1, +2, +3, +4, +5, +7 Comparar Estados de oxidação de todos os elementos →
- Elétrons de valência
- 7 Comparar Elétrons de valência de todos os elementos →
- Configuração eletrônica
- [Ar] 4s2 3d10 4p5
Termodinâmica
- Ponto triplo (temperatura)
- -7,25 °C
- Ponto triplo (pressão)
- 5879 Pa
- Ponto crítico (temperatura)
- 315 °C
- Ponto crítico (pressão)
- 1,034e+7 Pa
- Calor de fusão
- 0,10955071 eV Comparar Calor de fusão de todos os elementos →
- Calor de vaporização
- 0,31051459 eV Comparar Calor de vaporização de todos os elementos →
- Calor de atomização
- 1,159766 eV
- Entalpia de atomização
- 1,159248 eV
Nuclear
- Prótons
- 35 Comparar Prótons de todos os elementos →
- Nêutrons
- 44 Comparar Nêutrons de todos os elementos →
- Isótopos conhecidos
- 34 Comparar Isótopos conhecidos de todos os elementos →
- Isótopos estáveis
- 2 Comparar Isótopos estáveis de todos os elementos →
- Isótopo mais estável
- Br-79
- Ano da descoberta
- 1825
Abundância
- Abundância (crosta terrestre)
- 2,4 mg/kg Comparar Abundância (crosta terrestre) de todos os elementos →
- Abundância (oceano)
- 67,3 mg/L Comparar Abundância (oceano) de todos os elementos →
Estrutura cristalina
- Constante de rede a
- 667 pm
Estrutura eletrônica
- Elétrons por camada
- 2, 8, 18, 7 Comparar Elétrons por camada de todos os elementos →
Identificadores
- Número CAS
- 7726-95-6 Comparar Número CAS de todos os elementos →
- Símbolo de termo
- 2P°3/2
- InChI
- InChI=1S/Br
- Chave InChI
- WKBOTKDWSSQWDR-UHFFFAOYSA-N
Configuração eletrônica Medido
Br: 3d¹⁰ 4s² 4p⁵[Ar] 3d¹⁰ 4s² 4p⁵1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁵Modelo atômico
Os isótopos alteram o número de nêutrons, a massa e a estabilidade — não a configuração eletrônica de um átomo neutro.
Modelo atômico esquemático, sem escala.
Assinatura atômica
Espectro de emissão / absorção
Distribuição isotópica
| Número de massa | Massa atômica (u) | Abundância natural | Meia-vida |
|---|---|---|---|
| 79 Estável | 78,9183376 ± 0,0000014 | 50,6900% | Estável |
| 81 Estável | 80,9162897 ± 0,0000014 | 49,3100% | Estável |
Fase / Estado
Motivo: entre o ponto de fusão (-7,2 °C) e o ponto de ebulição (58,8 °C)
Esquemático, sem escala
Pontos de transição de fase
Energias de transição
Energia necessária para fundir 1 mol no ponto de fusão
Energia necessária para vaporizar 1 mol no ponto de ebulição
Densidade
Em condições padrão
Indisponível para a fase líquida
Avançado
Espectros atômicos
Mostrando 10 de 35. Ordenado por carga do íon (ordem crescente).
Dados de linhas disponíveis ?
| Íon | Carga | Total de linhas | Probabilidades de transição | Designações dos níveis |
|---|---|---|---|---|
| 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 |
Dados de níveis disponíveis ?
| Íon | Carga | Níveis |
|---|---|---|
| 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 |
Raios iônicos
| Carga | Coordenação | Spin | Raio |
|---|---|---|---|
| -1 | 6 | N/D | 196 pm |
| +3 | 4 | N/D | 59 pm |
| +5 | 3 | N/D | 31 pm |
| +7 | 4 | N/D | 25 pm |
| +7 | 6 | N/D | 39 pm |
Compostos
Isótopos (2)
| Número de massa | Massa atômica (u) | Abundância natural | Meia-vida | Modo de decaimento | |
|---|---|---|---|---|---|
| 79 Estável | 78,9183376 ± 0,0000014 | 50,6900% ± 0,0700% | Estável | stable | |
| 81 Estável | 80,9162897 ± 0,0000014 | 49,3100% ± 0,0700% | Estável | stable |
Propriedades ampliadas
Raios covalentes (dados ampliados)
- Raio covalente (Pyykkö)
- 114 pm
- Raio covalente (Pyykkö, ligação dupla)
- 109 pm
- Raio covalente (Pyykkö, ligação tripla)
- 110 pm
- Raio covalente (Bragg)
- 119 pm
Raios de van der Waals
- Bondi
- 183 pm
- Batsanov
- 190 pm
- Alvarez
- 186 pm
- UFF
- 418,9 pm
- MM3
- 222 pm
- Dreiding
- 395 pm
- Rowland–Taylor
- 187 pm
Raios atômicos e metálicos
- Raio atômico (Rahm)
- 219 pm
- Raio metálico (C12)
- 117 pm
Escalas de numeração
- Mendeleev
- 108
- Pettifor
- 98
- Glawe
- 100
Escalas de eletronegatividade
- Ghosh
- 0
- Gunnarsson–Lundqvist
- 8
- Robles–Bartolotti
- 7
Polarizabilidade e dispersão
- Polarizabilidade dipolar
- 21 a.u.
- Polarizabilidade dipolar (incerteza)
- 1 a.u.
- C₆
- 162 Ha·Bohr6
- C₆ (Gould–Bučko)
- 187 Ha·Bohr6
Afinidade química
- Afinidade protônica
- 554,4 kJ/mol
- Basicidade em fase gasosa
- 531,2 kJ/mol
Risco de abastecimento e economia
- Concentração da produção
- 44
- Risco relativo de abastecimento
- 7
- Distribuição das reservas
- 64
- Estabilidade política (maior produtor)
- 57
- Estabilidade política (detentor das maiores reservas)
- 57
Transições de fase e alótropos
| Ponto de fusão | 265,95 K |
| Ponto de ebulição | 331,95 K |
| Ponto crítico (temperatura) | 588,15 K |
| Ponto crítico (pressão) | 10,34 MPa |
| Ponto triplo (temperatura) | 265,9 K |
| Ponto triplo (pressão) | 5,88 kPa |
Categorias de estados de oxidação
Dados de referência avançados
Constantes de blindagem (8)
| n | Orbital | 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 |
Detalhes dos raios cristalinos (5)
| Carga | CN | Spin | rcrystal (pm) | Origem |
|---|---|---|---|---|
| -1 | VI | 182 | Pauling's (1960) crystal radius, | |
| 3 | IVSQ | 73 | ||
| 5 | IIIPY | 45 | ||
| 7 | IV | 39 | ||
| 7 | VI | 53 | Ahrens (1952) ionic radius, |
Modos de decaimento dos isótopos (54)
| Isótopo | Modo | Intensidade |
|---|---|---|
| 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% |
Fatores de espalhamento de raios X (506)
| Energia (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 |
Dados adicionais
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
2.4 milligrams per kilogram
Referências (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
6.73×101 milligrams per liter
Referências (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.
Referências (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.
Referências (1)
- [6] Bromine https://periodic.lanl.gov/35.shtml
Referências
(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.
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 Bromine.
The element property data was retrieved from publications.