Bromine (Br)
Bromum
Bromine (Br) is a halogen in period 4, group 17. Its relative atomic mass is 79.904 and the molar mass of the atom is 79.904 g/mol; the molar mass of Br₂ is 159.808 g/mol.
Atomic number 35
Atomic mass 79.904
Molar mass 79.904 g/mol Br₂: 159.808 g/mol
Category Halogen Liquid
Properties of bromine
| Atomic number | 35 |
|---|---|
| Symbol | Br |
| Latin name | Bromum |
| Relative atomic mass | 79.904 |
| Molar mass | 79.904 g/mol · Br₂: 159.808 g/mol |
| Group, period, block | 17, 4, p |
| Category | Halogen |
| State at 20 °C | Liquid |
| Electron configuration | [Ar] 3d¹⁰ 4s² 4p⁵ |
| Electronegativity (Pauling) | 2.96 |
| Atomic radius | 115 pm |
Electron configuration of bromine
Electrons per shell
K2L8M18N7
Full notation
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁵
Noble-gas notation
35 protons · 35 electrons[Ar] 3d¹⁰ 4s² 4p⁵
Formula and compounds of bromine
Simple substanceBr₂bromineMolar mass of Br₂: 159.808 g/mol
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Frequently asked questions
The relative atomic mass of bromine is 79.904, so the molar mass of the atom is 79.904 g/mol; the molar mass of Br₂ is 159.808 g/mol.
Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁵. Noble-gas notation: [Ar] 3d¹⁰ 4s² 4p⁵.