56
Ba
137.33
Barium
Element 56 · 137.33 u · s-block
alkaline earth
A soft, silvery alkaline earth metal. Barium sulfate is used as a radiocontrast agent for X-ray imaging of the digestive system.
Phase (STP)
Solid
Melting Point
727 °C
Boiling Point
1845 °C
Density
3.594 g/cm³
Electronegativity
0.89
Atomic Radius
215 pm
Ionization Energy
503 kJ/mol
Electron Affinity
14 kJ/mol
Discovered
1808 · Humphry Davy
Electron Configuration
[Xe] 6s2
Electron Orbitals
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