Technical data for Barium

Overview Name Barium Symbol Ba Atomic Number 56 Atomic Weight 137.327 Density 3.51 g/cm3 Melting Point 727 °C Boiling Point 1870 °C Thermal properties Phase Solid Melting Point 727 °C Boiling Point 1870 °C Absolute Melting Point 1000 K Absolute Boiling Point 2143 K Critical Pressure N/A Critical Temperature N/A Heat of Fusion 8 kJ/mol Heat of Vaporization 140 kJ/mol Specific Heat 205 J/(kg K)[note] Adiabatic Index N/A Neel Point N/A Thermal Conductivity 18 W/(m K) Thermal Expansion 0.0000206 K-1 Bulk physical properties Density 3.51 g/cm3 Density (Liquid) 3.338 g/cm3 Molar Volume 0.000039125 Brinell Hardness N/A Mohs Hardness 1.25 Vickers Hardness N/A Bulk Modulus 9.4 GPa Shear Modulus 4.9 GPa Young Modulus 13 GPa Poisson Ratio N/A Refractive Index N/A Speed of Sound 1620 m/s Thermal Conductivity 18 W/(m K) Thermal Expansion 0.0000206 K-1 Reactivity Valence 2 Electronegativity 0.89 ElectronAffinity 13.95 kJ/mol Ionization Energies 502.9, 965.2, 3600 kJ/mol Health and Safety DOT Hazard Class 4.3 DOT Numbers 1400 RTECS Number RTECSCQ8370000 NFPA Label

Classifications Alternate Names None Names of Allotropes None Block s Group 2 Period 6 Series Alkaline Earth Metal Electron Configuration [Xe]6s2 Color Silver Discovery 1808 in The United Kingdom Gas phase N/A CAS Number CAS7440-39-3 CID Number CID5355457 RTECS Number RTECSCQ8370000 Electrical properties Electrical Type Conductor Electrical Conductivity 2.9×106 S/m Resistivity 3.5×10-7 m Ω Superconducting Point N/A Magnetic properties Magnetic Type Paramagnetic Curie Point N/A Mass Magnetic Susceptibility 1.13×10-8 m3/Kg Molar Magnetic Susceptibility 1.552×10-9 m3/mol Volume Magnetic Susceptibility 0.00003966 Abundances % in Universe 1×10-6% % in Sun 9.9×10-7% % in Meteorites 0.00027% % in Earth's Crust 0.034% % in Oceans 3×10-6% % in Humans 0.00003% Atomic dimensions and structure Atomic Radius 253 pm Covalent Radius 215 pm Van der Waals Radius N/A Crystal Structure Body-centered Cubic Lattice Angles π/2, π/2, π/2 Lattice Constants 502.8, 502.8, 502.8 pm Space Group Name Im_ 3m Space Group Number 229 Nuclear Properties Half-Life Stable Lifetime Stable Decay Mode N/A Quantum Numbers 1S0 Neutron Cross Section 1.3 Neutron Mass Absorption 0.00027 Known Isotopes 114Ba, 115Ba, 116Ba, 117Ba, 118Ba, 119Ba, 120Ba, 121Ba, 122Ba, 123Ba, 124Ba, 125Ba, 126Ba, 127Ba, 128Ba, 129Ba, 130Ba, 131Ba, 132Ba, 133Ba, 134Ba, 135Ba, 136Ba, 137Ba, 138Ba, 139Ba, 140Ba, 141Ba, 142Ba, 143Ba, 144Ba, 145Ba, 146Ba, 147Ba, 148Ba, 149Ba, 150Ba, 151Ba, 152Ba, 153Ba Stable Isotopes 130Ba, 132Ba, 134Ba, 135Ba, 136Ba, 137Ba, 138Ba Isotopic Abundances 130Ba 0.106% 132Ba 0.101% 134Ba 2.417% 135Ba 6.592% 136Ba 7.854% 137Ba 11.232% 138Ba 71.698%