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Barium

Metalsolid
Symbol: Ba
Atomic number: 56
Atomic mass: 137.327
Group: Alkali Earth Metal
CAS-number: 7440-39-3

Physical data
Isotopes
Other info
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Physical data

Electronic data

Shells: 2, 8, 18, 18, 8, 2
Orbitals: [Xe] 6s2
Electronegativity: 0.9, 1.0
1. Ionization potential: 5.2117 eV
2. Ionization potential: 10.004 eV
3. Ionization potential: -- eV
Oxidation states: 2
Electrical conductivity: 0.030 10^6

Thermal data

Melting point: 725 °C
Boiling point: 1897 °C
Specific heat: 0.204 J/gK
Heat of fusion: 7.750 kJ/mol
Heat of vaporization: 142.0 kJ/mol
Thermal conductivity: 0.184 W/cmK

Steric data

Atomic radius: 2.78 Å
Ionic radius: 1.42 Å (+2)
Covalent radius: 1.98 Å
Atomic volume: 39.24 cm³/mol
Density (293 K): 3.51 g/cm³
Crystal structure: cubic body centered
cubic body centered

Isotopes

NuclideAbundance [%]MassSpinHalflifeDecay modeDecay tree
130Ba 0.101 129.906 0 -- --
131Ba 0 131 1/2 11.7d EC, β+ View
132Ba 0.097 131.905 0 -- --
133Ba 0 133 1/2 10.53y EC View
133Bam 0 133 11/2 1.621d IT, EC View
134Ba 2.42 133.905 0 -- --
135Ba 6.59 134.906 3/2 -- --
135Bam 0 135 11/2 1.20d IT View
136Ba 7.81 135.905 0 -- --
137Ba 11.32 137.906 3/2 -- --
137Bam 0 137 11/2 2.552m IT View
138Ba 71.66 137.905 0 -- --
139Ba 0 139 7/2 1.396h β- View
140Ba 0 140 0 12.75d β- View
141Ba 0 141 3/2 18.3m β- View
142Ba 0 142 0 10.7m β- View

Other info

Name origin:Greek: barys (heavy or dense).
Description:Soft, slightly malleable, silvery-white metal.
Discovered by:Sir Humphrey Davy
Year:1808
Place:England
Sources:Found in barytine (BaSO4) and witherite (BaCO3), never found in pure form due to its reactivity. Must be stored under kerosene to remain pure.
Use(s):Barite, or barium sulfate (BaSO4), when ground is used as a filter for rubber, plastics, and resins. It is insoluable in water and so is used in X-rays of the digestive system. Barium nitrate, Ba(NO3)2, burns brilliant green and is used in fireworks