35
Br
Bromine
79.904
Bromine (Br)
HalogenGroup 17Period 4p-block-block
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.
Latin name: Bromum
Atomic Number
35
Atomic Mass
79.904 g/mol
Phase (STP)
Liquid
Electron Config.
[Ar] 3d¹⁰ 4s² 4p⁵
General
SymbolBr
Atomic Number35
Atomic Mass79.904 g/mol
CategoryHalogen
Group17
Period4
Blockp-block
Electron Configuration[Ar] 3d¹⁰ 4s² 4p⁵
Valence Electrons7
Colourreddish-brown
CAS NumberCAS7726-95-6
Physical Properties
Phase (STP)Liquid
Density3.1028 g/cm³
Melting Point-7.35°C · 18.77°F · 265.80 K
Boiling Point58.80°C · 137.84°F · 331.95 K
Atomic Properties
Atomic Radius94 pm
Electronegativity2.96 Pauling
Ionization Energy1140 kJ/mol
Oxidation States+7, +5, +3, +1, -1
Ion ChargeBr-/Br+
Crystal Structure
Crystal Structureorthorhombic (solid form)
Abundance
In Earth's Crust0.0300%
Discovery & History
Discovery Year1826
Discovered ByAntoine Jérôme Balard
Country of DiscoveryFrance
Isotopes of Bromine
| Isotope | Abundance | Half-life | Decay |
|---|---|---|---|
| Br-79 | 50.69% | Stable | — |
| Br-81 | 49.31% | Stable | — |