Br - Bromine
Bromine Element Information, Facts, Properties, Trends, Uses, Comparison with other elements
Bromine (from Ancient Greek:βρῶμος, brómos, meaning 'stench') is a chemical element with symbol Br, and atomic number 35. It is a halogen. The element was isolated independently by two chemists, Carl Jacob Löwig and Antoine Jerome Balard, in 1825–1826.
It belongs to group 17 of the periodic table having trivial name halogens. You can also download Printable Periodic Table of Elements Flashcards for Bromine in a PDF format.
Bromine Facts
Read key information and facts about element Bromine
| Name | Bromine |
| Atomic Number | 35 |
| Atomic Symbol | Br |
| Atomic Weight | 79.904 |
| Phase | Liquid |
| Color | Red |
| Appearance | - |
| Classification | Halogens |
| Natural Occurance | Primordial |
| Group in Periodic Table | 17 |
| Group Name | fluorine family |
| Period in Periodic Table | period 4 |
| Block in Periodic Table | p-block |
| Electronic Configuration | [Ar] 3d10 4s2 4p5 |
| Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 7 |
| Melting Point | 265.8 K |
| Boiling Point | 332 K |
| CAS Number | CAS7726-95-6 |
How to Locate Bromine on Periodic Table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 35 to find Bromine on periodic table.
Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Bromine on periodic table look for cross section of group 17 and period 4 in the modern periodic table.
Bromine History
The element Bromine was discovered by J. Balard and C. Löwig in year 1825 in France. Bromine was first isolated by J. Balard and C. Löwig in 1825. Bromine derived its name from the Greek bromos, meaning 'stench'.
| Discovered By | J. Balard and C. Löwig |
| Discovery Date | 1825 in France |
| First Isolation | 1825 |
| Isolated by | J. Balard and C. Löwig |
They both discovered the element in the autumn of 1825. Balard published his results the next year, but Löwig did not publish until 1827.
Bromine Uses
Bromine is used as a flame-retarder in plastics and electronics. It can also be used to cleanse and disinfect water, leading to its use in swimming pools and hot tubs.
Bromine Presence: Abundance in Nature and Around Us
The table below shows the abundance of Bromine in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
| ppb by weight (1ppb =10^-7 %) | ppb by atoms (1ppb =10^-7 %) | |
|---|---|---|
| Abundance in Universe | 7 | 0.1 |
| Abundance in Sun | - | - |
| Abundance in Meteorites | 1200 | 230 |
| Abundance in Earth's Crust | 3000 | 780 |
| Abundance in Oceans | 67300 | 5210 |
| Abundance in Humans | 2900 | 230 |
Crystal Structure of Bromine
The solid state structure of Bromine is Base Centered Orthorhombic.
The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.
Unit Cell Parameters
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)
| a | b | c |
|---|---|---|
| 672.65 pm | 464.51 pm | 870.23 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
| alpha | beta | gamma |
|---|---|---|
| π/2 | π/2 | π/2 |
The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.
The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.
| Space Group Name | Cmca |
| Space Group Number | 64 |
| Crystal Structure | Base Centered Orthorhombic |
| Number of atoms per unit cell | 2 |
The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centred cubic are 1,4,2 respectively.
Bromine Atomic and Orbital Properties
Bromine atoms have 35 electrons and the electronic shell structure is [2, 8, 18, 7] with Atomic Term Symbol (Quantum Numbers) 2P3/2.
| Atomic Number | 35 |
| Number of Electrons (with no charge) | 35 |
| Number of Protons | 35 |
| Mass Number | 80 |
| Number of Neutrons | 45 |
| Shell structure (Electrons per energy level) | 2, 8, 18, 7 |
| Electron Configuration | [Ar] 3d10 4s2 4p5 |
| Valence Electrons | 4s2 4p5 |
| Valence (Valency) | 5 |
| Main Oxidation States | -1, 1, 3, 5 |
| Oxidation States | -1, 1, 3, 4, 5, 7 |
| Atomic Term Symbol (Quantum Numbers) | 2P3/2 |
Bohr Atomic Model of Bromine - Electrons per energy level
| n | s | p | d | f |
|---|
Ground State Electronic Configuration of Bromine - neutral Bromine atom
Abbreviated electronic configuration of Bromine
The ground state abbreviated electronic configuration of Neutral Bromine atom is [Ar] 3d10 4s2 4p5. The portion of Bromine configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Ar]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 4s2 4p5, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Bromine
Complete ground state electronic configuration for the Bromine atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p5
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.
As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
Atomic Structure of Bromine
Bromine atomic radius is 94 pm, while it's covalent radius is 114 pm.
| Atomic Radius Calculated | 94 pm(0.94 Å) |
| Atomic Radius Empirical | 115 pm (1.15 Å) |
| Atomic Volume | 19.78 cm3/mol |
| Covalent Radius | 114 pm (1.14 Å) |
| Van der Waals Radius | 185 pm |
| Neutron Cross Section | 6.8 |
| Neutron Mass Absorption | 0.002 |
Spectral Lines of Bromine - Atomic Spectrum of Bromine
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules.
Spectral lines are the result of interaction between a quantum system and a single photon. A spectral line may be observed either as an emission line or an absorption line.
Spectral lines are highly atom-specific, and can be used to identify the chemical composition of any medium. Several elements, including helium, thallium, and caesium, were discovered by spectroscopic means. They are widely used to determine the physical conditions of stars and other celestial bodies that cannot be analyzed by other means.
Emission spectrum of Bromine
Absorption spectrum of Bromine
Bromine Chemical Properties: Bromine Ionization Energies and electron affinity
The electron affinity of Bromine is 324.6 kJ/mol.
| Valence | 5 |
| Electronegativity | 2.96 |
| ElectronAffinity | 324.6 kJ/mol |
Ionization Energy of Bromine
Ionization energy is the amount of energy required to remove an electron from an atom or molecule.in chemistry, this energy is expresed in kilocalories per mole (kcal/mol) or kilojoules per mole (kJ/mol).
Refer to table below for Ionization energies of Bromine
| Ionization energy number | Enthalpy - kJ/mol |
|---|---|
| 1st | 1139.9 |
| 2nd | 2103 |
| 3rd | 3470 |
| 4th | 4560 |
| 5th | 5760 |
| 6th | 8550 |
| 7th | 9940 |
| 8th | 18600 |
Bromine Physical Properties
Refer to below table for Bromine Physical Properties
| Density | 3.12 g/cm3(when liquid at m.p density is $3.12 g/cm3) |
| Molar Volume | 19.78 cm3/mol |
Elastic Properties
| Young Modulus | - |
| Shear Modulus | - |
| Bulk Modulus | 1.9 GPa |
| Poisson Ratio | - |
Hardness of Bromine - Tests to Measure of Hardness of Element
| Mohs Hardness | - |
| Vickers Hardness | - |
| Brinell Hardness | - |
Bromine Electrical Properties
Electrical resistivity measures element's electrical resistance or how strongly it resists electric current.The SI unit of electrical resistivity is the ohm-metre (Ω⋅m). While Electrical conductivity is the reciprocal of electrical resistivity. It represents a element's ability to conduct electric current. The SI unit of electrical conductivity is siemens per metre (S/m).
Bromine is a Insulator. Refer to table below for the Electrical properties of Bromine
| Electrical conductors | Insulator |
| Electrical Conductivity | 1e-10 S/m |
| Resistivity | 10000000000 m Ω |
| Superconducting Point | - |
Bromine Heat and Conduction Properties
| Thermal Conductivity | 0.12 W/(m K) |
| Thermal Expansion | - |
Bromine Magnetic Properties
| Magnetic Type | Diamagnetic |
| Curie Point | - |
| Mass Magnetic Susceptibility | -4.9e-9 m3/kg |
| Molar Magnetic Susceptibility | -7.83e-10 m3/mol |
| Volume Magnetic Susceptibility | -0.0000153 |
Optical Properties of Bromine
| Refractive Index | 1.001132 |
Acoustic Properties of Bromine
| Speed of Sound | - |
Bromine Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Bromine
| Melting Point | 265.8 K(-7.35 °C, 18.770 °F) |
| Boiling Point | 332 K(58.85 °C, 137.930 °F) |
| Critical Temperature | 588 K |
| Superconducting Point | - |
Enthalpies of Bromine
| Heat of Fusion | 5.8 kJ/mol |
| Heat of Vaporization | 14.8 kJ/mol |
| Heat of Combustion | - |
Bromine Isotopes - Nuclear Properties of Bromine
Bromine has 31 isotopes, with between 67 and 97 nucleons. Bromine has 2 stable naturally occuring isotopes.
Isotopes of Bromine - Naturally occurring stable Isotopes: 79Br, 81Br.
| Isotope | Z | N | Isotope Mass | % Abundance | T half | Decay Mode |
|---|---|---|---|---|---|---|
| 67Br | 35 | 32 | 67 | Synthetic | ||
| 68Br | 35 | 33 | 68 | Synthetic | ||
| 69Br | 35 | 34 | 69 | Synthetic | ||
| 70Br | 35 | 35 | 70 | Synthetic | ||
| 71Br | 35 | 36 | 71 | Synthetic | ||
| 72Br | 35 | 37 | 72 | Synthetic | ||
| 73Br | 35 | 38 | 73 | Synthetic | ||
| 74Br | 35 | 39 | 74 | Synthetic | ||
| 75Br | 35 | 40 | 75 | Synthetic | ||
| 76Br | 35 | 41 | 76 | Synthetic | ||
| 77Br | 35 | 42 | 77 | Synthetic | ||
| 78Br | 35 | 43 | 78 | Synthetic | ||
| 79Br | 35 | 44 | 79 | 50.69% | Stable | N/A |
| 80Br | 35 | 45 | 80 | Synthetic | Stable | |
| 81Br | 35 | 46 | 81 | 49.31% | Stable | N/A |
| 82Br | 35 | 47 | 82 | Synthetic | ||
| 83Br | 35 | 48 | 83 | Synthetic | ||
| 84Br | 35 | 49 | 84 | Synthetic | ||
| 85Br | 35 | 50 | 85 | Synthetic | ||
| 86Br | 35 | 51 | 86 | Synthetic | ||
| 87Br | 35 | 52 | 87 | Synthetic | ||
| 88Br | 35 | 53 | 88 | Synthetic | ||
| 89Br | 35 | 54 | 89 | Synthetic | ||
| 90Br | 35 | 55 | 90 | Synthetic | ||
| 91Br | 35 | 56 | 91 | Synthetic | ||
| 92Br | 35 | 57 | 92 | Synthetic | ||
| 93Br | 35 | 58 | 93 | Synthetic | ||
| 94Br | 35 | 59 | 94 | Synthetic | ||
| 95Br | 35 | 60 | 95 | Synthetic | ||
| 96Br | 35 | 61 | 96 | Synthetic | ||
| 97Br | 35 | 62 | 97 | Synthetic |
Regulatory and Health - Health and Safety Parameters and Guidelines
The United States Department of Transportation (DOT) identifies hazard class of all dangerous elements/goods/commodities either by its class (or division) number or name. The DOT has divided these materials into nine different categories, known as Hazard Classes.
NFPA 704 is a Standard System for the Identification of the Hazards of Materials for Emergency Response. NFPA is a standard maintained by the US based National Fire Protection Association.
The health (blue), flammability (red), and reactivity (yellow) rating all use a numbering scale ranging from 0 to 4. A value of zero means that the element poses no hazard; a rating of four indicates extreme danger.
| NFPA Fire Rating | 0 | Will not burn |
| NFPA Health Rating | 3 | Flash Points below 37.8°C (100°F) |
| NFPA Reactivity Rating | 0 | Will not burn |
| NFPA Hazards | OX | Oxidizing Agent |
| Autoignition Point | - |
| Flashpoint | -18 °C |
Database Search
List of unique identifiers to search the element in various chemical registry databases
| Database | Identifier number |
|---|---|
| CAS Number - Chemical Abstracts Service (CAS) | CAS7726-95-6 |
| RTECS Number | RTECSEF9100000 |
| CID Number | CID24408 |
| Gmelin Number | - |
| NSC Number | - |
Compare Bromine with other elements
Compare Bromine with Group 17, Period 4 and Halogens elements of the periodic table.
Compare Bromine with all Group 17 elements
Compare Bromine with all Period 4 elements
Compare Bromine with all Halogens elements
Frequently Asked Questions (FAQ)
Find the answers to the most frequently asked questions about Bromine