Barium (Ba)
Barium (Ba) is element 56 of the periodic table, an alkaline earth metal in period 6 and group 2. Its standard atomic weight is 137.327, so one mole of barium atoms has a mass of 137.327 g. At room temperature it is a solid; it melts at 726.85 °C and boils at 1896.85 °C.
| Atomic number | 56 |
|---|---|
| Symbol | Ba |
| Standard atomic weight | 137.327 |
| Molar mass | 137.327 g/mol |
| Category | Alkaline earth metal |
| Group | 2 |
| Period | 6 |
| Block | s-block |
| Electron configuration | [Xe] 6s2 |
| Oxidation states | +2 |
| Electronegativity (Pauling) | 0.89 |
| Atomic radius (van der Waals) | 268 pm |
| First ionisation energy | 5.212 eV (502.9 kJ/mol) |
| Electron affinity | — |
| State at room temperature | Solid |
| Melting point | 1000 K (726.85 °C) |
| Boiling point | 2170 K (1896.85 °C) |
| Density | 3.62 g/cm³ |
| Discovered | 1808 |
Group 2
Calculate with Barium
Atomic weight: IUPAC CIAAW standard atomic weight. Other properties: PubChem (U.S. National Library of Medicine, public domain). Values such as melting point and radius depend on how they were measured; check a data book for precise work.