Barium
Barium (钡, symbol Ba) is chemical element number 56, an Alkaline Earth in period 6, group 2 of the periodic table, with a standard atomic weight of about 137.33. Soft, silvery alkaline earth metal. Used in drilling fluids and as a contrast agent in medicine.
Properties
| Atomic number | 56 |
|---|---|
| Symbol | Ba |
| Atomic mass | 137.33 u |
| Category | Alkaline Earth |
| Period | 6 |
| Group | 2 |
| Electron configuration | [Xe] 6s² |
| Electronegativity | 0.89 |
| Covalent radius | 215 pm |
| Density | 3.62 g/cm³ |
| Melting point | 1000 K |
| Boiling point | 2170 K |
| Discovery | Humphry Davy, 1808 |
Overview
Soft, silvery alkaline earth metal. Used in drilling fluids and as a contrast agent in medicine. Barium (symbol Ba) is chemical element number 56, sitting in period 6, group 2 of the periodic table and classed as an Alkaline Earth. As an alkaline-earth metal it is a little less reactive than the alkali metals and occurs in nature mainly within mineral compounds.
Its electron configuration is [Xe] 6s², with 2 electrons in the outer shell, and an electronegativity of about 0.89 (Pauling). Around 25 °C it is usually a solid; it melts near 1000 K (726.9 °C), boils near 2170 K (1896.9 °C), has a density around 3.62 g/cm³.
In industry and daily life it turns up in Medical / Pharma and Structural / Alloys. It is regarded as a moderate-hazard element, so handle it with appropriate care. It was first described by Humphry Davy in 1808.
Electron shells
Electrons per shell: 2 · 8 · 18 · 18 · 8 · 2
Main uses
- Medical / Pharma
- Structural / Alloys
Hazard
Compounds containing Barium
No compounds in this knowledge base contain Barium yet.
Data sources
Atomic mass uses IUPAC (CIAAW) standard atomic weights; the covalent radius is from Cordero et al. (2008). Verify on the RSC Periodic Table, PubChem and Wikipedia. Educational reference only.