35Br79.904
Bromine (Br)
Element 35 · Halogen
Bromine (Br) is a chemical element with atomic number 35. It is classified as a halogen in period 4, group 17 of the periodic table (the p-block). Its standard atomic weight is 79.904 u and its ground-state electron configuration is [Ar] 3d¹⁰ 4s² 4p⁵.
Bromine facts
| Atomic number (Z) | 35 |
|---|---|
| Symbol | Br |
| Standard atomic weight | 79.904 u |
| Category | Halogen |
| Group | 17 |
| Period | 4 |
| Block | p-block |
| Electron configuration | [Ar] 3d¹⁰ 4s² 4p⁵ |
| Electronegativity (Pauling) | 2.96 |
| State at 20 °C | Liquid |
| Protons / electrons | 35 / 35 |
| Neutrons (most common isotope, approx.) | 45 |
| Molar mass | 79.904 g/mol |