Bromine (Br)
Bromine (Br) is element 35, a halogen. Atomic mass 79.904, configuration [Ar] 3d¹⁰ 4s² 4p⁵. Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.
Key facts
| Atomic number | 35 |
|---|---|
| Symbol | Br |
| Standard atomic weight | [79.901,79.907] |
| Category | Halogen |
| Group | 17 |
| Period | 4 |
| State at room temperature | Liquid |
| Electron configuration | [Ar] 3d¹⁰ 4s² 4p⁵ |
| Valence electrons | 7 |
| Common oxidation states | -1, +1, +3, +5 |
| Common ions | Br⁻ |
| Electronegativity (Pauling) | 2.96 |
| First ionization energy | 1140 kJ/mol |
| Electron affinity | 324.5 kJ/mol |
| Atomic radius | 94 pm |
| Density | 3.103 g/cm³ |
| Melting point | -7.3°C |
| Boiling point | 58.80°C |
| Specific heat | 0.474 J/(g·°C) |
Natural isotopes
- Br-79: Stable
- Br-81: Stable
Common uses
- Flame retardants
- Drilling fluids
- Photographic film (AgBr)
Where it matters
- Flame retardants
- Ozone depletion
Hazards
- Corrosive liquid
- vapor is highly toxic
History
| Discovered | 1826 |
|---|---|
| Discovered by | Antoine Jérôme Balard |
| Name | From Greek bromos (stench) |