56 Ba 137.33
Barium
Alkaline Earth Metal
Barium (Ba) is a chemical element with atomic number 56, classified as a alkaline earth metal. At room temperature it is a solid. It was discovered in 1808 by Humphry Davy.
Properties
- Atomic number
- 56
- Atomic mass
- 137.33 u
- Category
- Alkaline Earth Metal
- Group
- 2
- Period
- 6
- Block
- s-block
- Electron configuration
- [Xe] 6s²
- Phase at STP
- Solid
- Density
- 3.594 g/cm³
- Melting point
- 1000 K (726.9 °C)
- Boiling point
- 2170 K (1896.8 °C)
- Electronegativity
- 0.89
- Atomic radius
- 253 pm
- Ionization energy
- 5.212 eV
- Discovery
- 1808 · Humphry Davy
Common uses
Medical imaging, fireworks, drilling mud, magnets
Did you know?
Creates green color in fireworks and used in medical X-ray imaging.
Compounds you can make with barium
Barium appears in 2 compounds in our periodic table sandbox. Each one is a real substance with its true chemical formula — combine the right elements in the right ratio below to discover it.
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BaCl2
Barium Chloride
A soluble barium salt used in labs to test for sulfate and to give fireworks a green flash.
-
BaSO4
Barium Sulfate
The mineral barite — so insoluble that patients safely drink it as X-ray contrast.