Br 35

Bromine (Br)

halogen
Period: 4 Group: 17 Block: p

Liquid

Standard Atomic Weight

79.904 u [79.901, 79.907]

Electron configuration

[Ar] 4s2 3d10 4p5

Melting point

-7.2 °C (265.95 K)

Boiling point

58.8 °C (331.95 K)

Density

3102.8 kg/m³

Oxidation states

−1, +1, +2, +3, +4, +5, +7

Electronegativity (Pauling)

2.96

Ionization energy (1st)

Discovery year

1825

Atomic radius

115 pm

Details

Name origin Greek: brômos (stench).
Discovery country France
Discoverers Antoine J. Balard

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.

Images

Properties

Physical

Atomic radius (empirical) 115 pm
Covalent radius 120 pm
Van der Waals radius 183 pm
Density
Molar volume 0.0235 L/mol
Phase at STP liquid
Melting point -7.2 °C
Boiling point 58.8 °C
Thermal conductivity 0.005 W/(m·K)
Specific heat capacity 0.474 J/(g·K)
Molar heat capacity 75.69 J/(mol·K)
Crystal structure orthorhombic

Chemical

Electronegativity (Pauling) 2.96
Electronegativity (Allen) 2.685
Electron affinity
Ionization energy (1st)
Ionization energy (2nd)
Ionization energy (3rd)
Ionization energy (4th)
Ionization energy (5th)
Oxidation states −1, +1, +2, +3, +4, +5, +7
Valence electrons 7
Electron configuration
Electron configuration (semantic)

Thermodynamic

Triple point (temperature) -7.25 °C
Triple point (pressure) 5879 Pa
Critical point (temperature) 315 °C
Critical point (pressure) 1.034000e+7 Pa
Heat of fusion 0.10955071 eV
Heat of vaporization 0.31051459 eV
Heat of atomization 1.159766 eV
Atomization enthalpy

Nuclear

Stable isotopes 2
Discovery year 1825

Abundance

Abundance (Earth's crust) 2.4 mg/kg
Abundance (ocean)

Reactivity

N/A

Crystal Structure

Lattice constant a 667 pm

Electronic Structure

Electrons per shell 2, 8, 18, 7

Identifiers

CAS number 7726-95-6
Term symbol
InChI InChI=1S/Br
InChI Key WKBOTKDWSSQWDR-UHFFFAOYSA-N

Electron Configuration Measured

Ion charge
Protons 35
Electrons 35
Charge Neutral
Configuration Br: 3d¹⁰ 4s² 4p⁵
Electron configuration
Measured
[Ar] 3d¹⁰ 4s² 4p⁵
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁵
Orbital diagram
1s
2/2
2s
2/2
2p
6/6
3s
2/2
3p
6/6
4s
2/2
3d
10/10
4p
5/6 1↑
Total electrons: 35 Unpaired: 1 ?

Atomic model

Protons 35
Neutrons 44
Electrons 35
Mass number 79
Stability Stable

Isotopes change neutron count, mass, and stability — not the electron configuration of a neutral atom.

Schematic atomic model, not to scale.

Atomic Fingerprint

Emission / Absorption Spectrum

0 / 0 (0 with intensity)
Measured
Emission Visible: 380–750 nm

Isotope Distribution

7950.6900%8149.3100%Mass numberNatural abundance (%)
Mass numberAtomic mass (u)Natural abundanceHalf-life
79 Stable78.9183376 ± 0.000001450.6900%Stable
81 Stable80.9162897 ± 0.000001449.3100%Stable
Measured

Phase / State

1 atm / 101.325 kPa
Liquid 25 °C (298.15 K)

Reason: between melting point (-7.2 °C) and boiling point (58.8 °C)

Melting point -7.2 °C
Boiling point 58.8 °C
Relative to transitions Between transitions
0 K Current temperature: 25 °C 6000 K
Phase timeline

Schematic, not to scale

Solid
Liquid
Gas
Melting
Boiling
25°C
Solid
Liquid
Gas
Current

Phase transition points

Melting point Literature
-7.2 °C
Boiling point Literature
58.8 °C
Current phase Calculated
Liquid

Transition energies

Heat of fusion Literature
0.10955071 eV

Energy required to melt 1 mol at melting point

Heat of vaporization Literature
0.31051459 eV

Energy required to vaporize 1 mol at boiling point

Density

Reference density Literature
3102.8 kg/m³

At standard conditions

Current density Calculated
N/A

Not available for liquid phase

Advanced

Triple point Literature
-7.25 °C
Critical point Literature
315 °C

Atomic Spectra

Showing 10 of 35 Atomic Spectra. Sorted by ion charge (ascending).

Lines Holdings ?

IonChargeTotal linesTransition probabilitiesLevel designations
Br I 017054170
Br II +111830
Br III +27500
Br IV +31360136
Br V +42200
NIST Lines Holdings →

Levels Holdings ?

IonChargeLevels
Br I 0265
Br II +1132
Br III +253
Br IV +343
Br V +410
Br VI +512
Br VII +66
Br VIII +712
Br IX +85
Br X +92
NIST Levels Holdings →
35 Br 79.904

Bromine — Atomic Orbital Visualizer

[Ar]4s23d104p5
Energy levels 2 8 18 7
Oxidation states -1, +1, +2, +3, +4, +5, +7
HOMO 4p n=4 · l=1 · m=-1
Bromine — Atomic Orbital Visualizer Preview
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35 Br 79.904

Bromine — Crystal Structure Visualizer

Orthorhombic · Pearson N/A
Experimental
Pearson N/A
No crystal structure at standard conditions — liquid at 298 K, 1 atm
Solid phase structure at 293 K
Bromine — Crystal Structure Visualizer Preview
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Ionic Radii

ChargeCoordinationSpinRadius
-16N/A196 pm
+34N/A59 pm
+53N/A31 pm
+74N/A25 pm
+76N/A39 pm

Compounds

Br-
79.900 u
Br
79.900 u
Br-
71.937 u
Br-
74.926 u
Br-
75.924 u
Br-
76.921 u
Br-
79.919 u
Br-
73.930 u
Br-
81.917 u
Br-
80.916 u
Br-
78.918 u

Isotopes (2)

Mass numberAtomic mass (u)Natural abundanceHalf-lifeDecay mode
79 Stable78.9183376 ± 0.000001450.6900% ± 0.0700%Stable
stable
81 Stable80.9162897 ± 0.000001449.3100% ± 0.0700%Stable
stable
79 Stable
Atomic mass (u) 78.9183376 ± 0.0000014
Natural abundance 50.6900% ± 0.0700%
Half-life Stable
Decay mode
stable
81 Stable
Atomic mass (u) 80.9162897 ± 0.0000014
Natural abundance 49.3100% ± 0.0700%
Half-life Stable
Decay mode
stable

Extended Properties

Covalent Radii (Extended)

Covalent radius (Pyykkö)  
Covalent radius (Pyykkö, double)  
Covalent radius (Pyykkö, triple)  
Covalent radius (Bragg)  

Van der Waals Radii

Bondi  
Batsanov  
Alvarez  
UFF  
MM3  
Dreiding  
Rowland–Taylor  

Atomic & Metallic Radii

Atomic radius (Rahm)  
Metallic radius (C12)  

Numbering Scales

Mendeleev
Pettifor
Glawe

Electronegativity Scales

Ghosh
Gunnarsson–Lundqvist
Robles–Bartolotti

Polarizability & Dispersion

Dipole polarizability  
Dipole polarizability (unc.)  
C₆  
C₆ (Gould–Bučko)  

Chemical Affinity

Proton affinity  
Gas basicity  

Supply Risk & Economics

Production concentration
Relative supply risk
Reserve distribution
Political stability (top producer)
Political stability (top reserve)

Phase Transitions & Allotropes

Melting point265.95 K
Boiling point331.95 K
Critical point (temperature)588.15 K
Critical point (pressure)10.34 MPa
Triple point (temperature)265.9 K
Triple point (pressure)5.88 kPa

Oxidation State Categories

+2 extended
+3 main
+1 main
−1 main
+7 extended
+5 main
+4 extended

Advanced Reference Data

Screening Constants (8)
nOrbitalσ
1s0.7529
2p3.9436
2s9.3566
3d15.4409
3p15.4292
3s14.7815
4p25.972
4s24.4472
Crystal Radii Detail (5)
ChargeCNSpinrcrystal (pm)Origin
-1VI182Pauling's (1960) crystal radius,
3IVSQ73
5IIIPY45
7IV39
7VI53Ahrens (1952) ionic radius,
Isotope Decay Modes (54)
IsotopeModeIntensity
65p
66p
67p
68p
69p100%
70B+100%
70B+p
71B+100%
72B+100%
73B+100%
X‑ray Scattering Factors (506)
Energy (eV)f₁f₂
105.16199
10.16175.31855
10.32615.47986
10.49315.64606
10.66285.8173
10.83535.99373
11.01066.17552
11.18866.36281
11.36966.5558
11.55356.75463

Additional Data

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.

References (1)

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.

References (1)

References

(9)
2 Atomic Mass Data Center (AMDC), International Atomic Energy Agency (IAEA)
Br

The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.

3 IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW)
Bromine

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.

4 IUPAC Periodic Table of the Elements and Isotopes (IPTEI)

The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.

License note: Copyright (c) 2020 International Union of Pure and Applied Chemistry. The International Union of Pure and Applied Chemistry (IUPAC) contribution within Pubchem is provided under a CC-BY-NC-ND 4.0 license, unless otherwise stated.
5 Jefferson Lab, U.S. Department of Energy
Bromine

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/

License note: Please see citation and linking information: https://education.jlab.org/faq/index.html
6 Los Alamos National Laboratory, U.S. Department of Energy
Bromine

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.

7 NIST Physical Measurement Laboratory
Bromine

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

8 PubChem Elements
Bromine

This section provides all form of data related to element Bromine.

9 PubChem Elements
Bromine

The element property data was retrieved from publications.

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Data verified:

Content is reviewed against latest scientific data.