35 Br Bromine 79.904
Halogen
Bromine 溴
[Ar] 3d¹⁰ 4s² 4p⁵
- Period 4
- Group 17
- Block p
- Liquid
Electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁵
Orbital diagram (valence)
4s ↑↓
4p ↑↓↑↓↑
- Electrons per shell
- 2, 8, 18, 7
- Unpaired electrons
- 1
- Zeff (Slater)
- 7.60
Properties
- Atomic weight
- 79.904
- Electronegativity (Pauling)
- 2.96
- First ionization energy
- 1140 kJ/mol
- Electron affinity
- 324.7 kJ/mol
- Covalent radius
- 120 pm
- van der Waals radius
- 183 pm
- Melting point
- 265.9 K
- Boiling point
- 331.9 K
- Density
- 3.11 g/cm³
- Melting / boiling point
- −7.2 °C / 58.8 °C
- Common oxidation states
- +5, +1, −1
- Discovered
- 1826
Natural isotopes
| Mass number A | Atomic mass / u | Abundance |
|---|---|---|
| 79Br | 78.918338 | 50.69 % |
| 81Br | 80.916290 | 49.31 % |
Isotope masses: AME2020; abundances: IUPAC/CIAAW representative values.
Bromine in the course
The lessons that discuss this element most (ranked by mentions).
- Halogens and noble gases The main-group elements
- Hess’s law and enthalpies of formation Thermochemistry
- Mass spectrometry: isotope clusters and fragments Spectroscopic analysis
- Ligand substitution: labile and inert Coordination chemistry
- Complex ions and formation constants Precipitation and complex ions
Lab experiments with Bromine
Periodic trend
Group 17
Data: PubChem periodic table (public domain); atomic weights are IUPAC abridged standard values; covalent radii from Cordero et al. (2008).