56Ba137.33
Barium (Ba)
Element 56 Ā· Alkaline earth metal
Barium (Ba) is a chemical element with atomic number 56. It is classified as an alkaline earth metal in period 6, group 2 of the periodic table (the s-block). Its standard atomic weight is 137.33 u and its ground-state electron configuration is [Xe] 6sĀ².
Barium facts
| Atomic number (Z) | 56 |
|---|---|
| Symbol | Ba |
| Standard atomic weight | 137.33 u |
| Category | Alkaline earth metal |
| Group | 2 |
| Period | 6 |
| Block | s-block |
| Electron configuration | [Xe] 6sĀ² |
| Electronegativity (Pauling) | 0.89 |
| State at 20 Ā°C | Solid |
| Protons / electrons | 56 / 56 |
| Neutrons (most common isotope, approx.) | 81 |
| Molar mass | 137.33 g/mol |