31Ga69.723
Gallium (Ga)
Element 31 · Post-transition metal
Gallium (Ga) is a chemical element with atomic number 31. It is classified as a post-transition metal in period 4, group 13 of the periodic table (the p-block). Its standard atomic weight is 69.723 u and its ground-state electron configuration is [Ar] 3d¹⁰ 4s² 4p¹.
Gallium facts
| Atomic number (Z) | 31 |
|---|---|
| Symbol | Ga |
| Standard atomic weight | 69.723 u |
| Category | Post-transition metal |
| Group | 13 |
| Period | 4 |
| Block | p-block |
| Electron configuration | [Ar] 3d¹⁰ 4s² 4p¹ |
| Electronegativity (Pauling) | 1.81 |
| State at 20 °C | Solid |
| Protons / electrons | 31 / 31 |
| Neutrons (most common isotope, approx.) | 39 |
| Molar mass | 69.723 g/mol |