56 Ba (Barium)
It is a soft, metallic element (Pure barium is of silvery-white).
The metal oxidizes very easily in air, so it should be stored in mineral oil or other suitable oxygen-free liquids to prevent from contact with air.
It is decomposed by water or alcohol.
Barium forming often poisoning compounds by reacts with almost all non-metals.
Commonly barium sold is about 99% pure, with main impurities strontium (upto 0.8%) and calcium (upto 0.25 %).
CAS Number: CAS7440-39-3
CID Number: CID5355457
DOT Hazard Class: 4.3
DOT Number: 1400
RTECS Number: RTECSCQ8370000
Basic Properties of Barium
Appearance: Silvery gray; with pale yellow tint
Mass Number: 137
Standard Atomic weight: 137.327 g/mol
Atomic number (Z): 56
Element category: Alkaline earth metals
Electrons per shell: K2, L8, M18, N18, O8, P2
Electron configuration: 1s22s22p63s23p63d104s24p64d105s25p66s2
Thermal Properties of Barium
Melting point: 1000 K (727 oC, 1341 oF)
Boiling point: 2118 K (1845 oC, 3353 oF)
Fusion heat: 7.12 kJ/mol
Vaporization heat: 142 kJ/mol
Molar heat capacity: 28.07 J/(mol.K)
Thermal expansion: 20.6 μm/(m∙K)
Thermal conductivity: 18.4 W/(m∙K)
Electrical properties of Barium
Electrical conductivity: 2.9×106 S/m
A Electrical resistivity: 332 nΩ∙m
A Electrical type: Conductor
Magnetic Properties of Barium
A Magnetic type: Paramagnetic
Magnetic susceptibility (xmol): +20.6×10-6 cm3/mol
Volume magnetic susceptibility: 0.00003966
Mass magnetic susceptibility: 11.3×10-9 m3/kg
Molar magnetic susceptibility: 1.552×10-9 m3/mol
Physical Properties of Barium
Density: 3.51 g/cm3 (In solid) 3.338 g/cm3 (In Liquid)
Molar volume: 0.00003912 m3/mol
Young’s modulus: 13 GPa
Shear modulus: 4.9 GPa
Mohs Hardness: 1.25
Bulk modulus: 9.6 GPa
Sound Speed: 1620 m/s
Atomic Properties of Barium
Oxidation states: +2, +1
Valence Electrons: 6s2
Ion charge: Ba2+
Ionization Potential of an atom: 5.19
Ionization energies: 1st: 502.9 kJ.mol 2nd: 965.2 kJ/mol 3rd: 3600 kJ/mol
Ionic radius: 135 pm
Atomic radius: 268 pm (Van der Waals)
Covalent radius: 215±11 pm
Filling Orbital: 6s2
Crystal structure: Body-centered cubic
Lattice angles: π/2, π/2, π/2
Lattice constant: 502.8, 502.8, 502.8 pm
Grid parameters: 5.020 Å
Space Group Name: lm_3m
Space Group Number: 229
Reactivity of Barium
Electronegativity: Pauling scale: 0.89
Electron affinity: 13.95 kJ/mol
Nuclear Properties of Barium
Half Life: Stable (Infinity)
Lifetime: Stable (Infinity)
Quantum Number: 1S0
Neutron cross section (Brans): 1.3
Neutron Mass Absorption: 0.00027
Isotopes: 130Ba 132Ba 133Ba 134Ba 135Be 136Ba 137Ba 138Ba
|Isotope||Abundance (%)||Atomic Mass g/mol||Half Life (t1/2)|
The metal once ignited, burns readily to form Barium oxide and Barium nitride:
2 Ba(s) + O2(g) → 2BaO(s)
Ba(s) + O2(g) → BaO2(s)
3Ba(s) + N2(g) → Ba3N2(s)
Barium Reactions with water and alcohols are very exothermic and release hydrogen gas (R is alkyl group or a hydrogen atom)
Ba + 2 ROH → Ba(OR)2 + H2↑
Reacts Readily with water (slower than radium and quicker than strontium) to form Barium (lll) hydroxide and hydrogen gas:
Ba (s) + 2 H2O (l) → Ba(OH)2 (aq) + H2 (g)
React with Hydrogen (forming Barium hydride):
Ba(s) + H2(g) → BaH2 (s)
Barium reacts with hydrochloric acid and form a barium chloride:
Ba (s) + 2 HCl (aq) → Bacl2 (aq) + H2 (g)
Pure barite reduced by carbon to barium sulfide:
BaSO4 + 2 C → BaS + 2 CO2↑
The metal is produced by reduction with Aluminium:
3 Bao + 14 Al → 3 BaAl4 + Al2O3
Intermetallic compound (BaAl4) reacted with barium oxide to produce the metal.
8 BaO + BaAl4 → Ba↑ + 7 BaAl2O4
Remaining barium oxide reacts with the formed aluminium oxide (Al2O3):
BaO + Al2O3 → BaAl2O4
Overall reaction is:
4 BaO + 2 Al → 3 Ba↑ + BaAl2O4
(Barium vapour condensed and packed into molds in environment of argon)
Naming: Greek: Barys (heavy or dense)
Discovery: Carl Wilhelm Scheele (1772)
First isolation: Humphry Davy (1808) in London
The most important barium compounds are chloride, carbonate, sulfate, peroxide, nitrate, and chlorate.
Barium alloys with calcium, silicon, manganese, and aluminum as high-grade steel deoxidizers.
Barium is used in barium-nickel alloys for spark-plug electrodes.
Barium-aluminium alloyed is used to remove unwanted gases (gettering) from vacuum tubes, such as TV picture tubes
Barium compounds are used as a weighing agent in drilling fluids for oil and gas wells, and also used to in making paint, glass, tiles, bricks, and rubber.
‘barium meal’ or ‘barium enema’ known as Barium Sulphate.
Barium sulfate is insoluble and it has low toxicity, so it can be given sometimes to patients suffering from digestive disorders.
Due to high opacity, It is also used in X-rays diagnostic work. Because it is a contrast agent that is used to better visualize the gastro-intestinal tract via radiology. where, the X-rays show a complete picture of the gastro-intestinal tract.
The impure barium sulfide phosphoresces after exposure to the light.
Barium carbonate has been used in the past as a rat poison, while the nitrate and chlorate give fireworks a green colour.
It is toxic.
All barium compounds that are water or acid soluble are poisonous
Higher doses affect the nervous system, causing cardiac irregularities, anxiety, tremors, shortness of breath, weakness, and paralysis.
Abundance of Barium
It is found only in combination with other elements, never found in pure form due to its reactivity.
Its found in Barite (barium sulfate BaSO4) and witherite (Baium carbonate BaCO3)
The metal is prepared by electrolysis of the molten barium chloride, or by heating barium oxide with aluminium.
Annual world wide production is around 6,000,000 tons.
5×10-7% (In Universe)
1.7×10-5% (In Meteorites)
1×10-7% (In Sun)
0.0008% (In Earth’s Crust)
4.5×10-11% (In Oceans)
World’s Top 3 producers of Barium
World’s Top 3 Reserve holders of Barium