Bromine (Br)
Bromine is the chemical element with atomic number 35 and symbol Br. It is a reactive nonmetal in period 4, group 17, with a standard atomic weight of 79.904 u.
Key facts
- Z
- 35
- Atomic weight
- 79.904 u
- Category
- reactive nonmetal
- State at 298 K
- Liquid
- Occurrence
- primordial
- Discovered
- 1825
Measured properties
| Property | Value | Source |
|---|---|---|
| Electronegativity | 2.96 | National Center for Biotechnology Information (NIH) |
| Melting point | 265.95 K | National Center for Biotechnology Information (NIH) |
| Boiling point | 331.95 K | National Center for Biotechnology Information (NIH) |
| Density stp | 3.11 g/cm³ | National Center for Biotechnology Information (NIH) |
| Atomic radius empirical | 183 pm | National Center for Biotechnology Information (NIH) |
| Ionization energy 1st | 1,139.9 kJ/mol | National Center for Biotechnology Information (NIH) |
| Electron affinity | 324.7 kJ/mol | National Center for Biotechnology Information (NIH) |
Electron configuration
- Noble gas notation
- [Ar] 3d¹⁰ 4s² 4p⁵
- Full notation
- 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁵
- Electrons per shell
- 2, 8, 18, 7