Ba
Barium
Atomic number: 56Mass: 137.327 uCategory: Alkaline Earth Metal
About Barium
Barium is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found as a free element in nature. It is used as a 'getter' in vacuum tubes to remove trace gases.
Properties
Period
6
Group
2
Block
S
Category
Alkaline Earth Metal
Electronegativity
0.89 (Pauling)
Ionization Energy
502.9 kJ/mol
Melting Point
1000 K (727°C)
Boiling Point
2118 K (1845°C)
Density
3.51 g/cm³
Oxidation States
+2
Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 6s²
[Xe] 6s²
Shell 1:2e⁻
Shell 2:8e⁻
Shell 3:18e⁻
Shell 4:18e⁻
Shell 5:8e⁻
Shell 6:2e⁻
Real-World Uses
Medical imaging (barium meal)
Fireworks (green colour)
Drilling mud
Glass manufacturing
Pigments
Fun Fact
When you have an X-ray of your digestive system, you swallow a barium sulfate 'milkshake' — barium absorbs X-rays and makes your gut visible!