Technical data for Rubidium

Overview Name Rubidium Symbol Rb Atomic Number 37 Atomic Weight 85.4678 Density 1.532 g/cm3 Melting Point 39.31 °C Boiling Point 688 °C Thermal properties Phase Solid Melting Point 39.31 °C Boiling Point 688 °C Absolute Melting Point 312.46 K Absolute Boiling Point 961 K Critical Pressure 16 MPa (157.9 Atm)[note] Critical Temperature 2093 K[note] Heat of Fusion 2.19 kJ/mol Heat of Vaporization 71 kJ/mol Specific Heat 364 J/(kg K)[note] Adiabatic Index N/A Neel Point N/A Thermal Conductivity 58 W/(m K) Thermal Expansion N/A Bulk physical properties Density 1.532 g/cm3 Density (Liquid) 1.46 g/cm3 Molar Volume 0.000055788 Brinell Hardness 0.216 MPa Mohs Hardness 0.3 Vickers Hardness N/A Bulk Modulus 2.5 GPa Shear Modulus N/A Young Modulus 2.4 GPa Poisson Ratio N/A Refractive Index N/A Speed of Sound 1300 m/s Thermal Conductivity 58 W/(m K) Thermal Expansion N/A Reactivity Valence 1 Electronegativity 0.82 ElectronAffinity 46.9 kJ/mol Ionization Energies 403, 2633, 3860, 5080, 6850, 8140, 9570, 13120, 14500, 26740 kJ/mol Health and Safety DOT Hazard Class 4.3 DOT Numbers 1423 RTECS Number RTECSVL8500000 NFPA Label

Classifications Alternate Names None Names of Allotropes None Block s Group 1 Period 5 Series Alkali Metal Electron Configuration [Kr]5s1 Color Silver Discovery 1861 in Germany Gas phase N/A CAS Number CAS7440-17-7 CID Number CID5357696 RTECS Number RTECSVL8500000 Electrical properties Electrical Type Conductor Electrical Conductivity 8.3×106 S/m Resistivity 1.2×10-7 m Ω Superconducting Point N/A Magnetic properties Magnetic Type Paramagnetic Curie Point N/A Mass Magnetic Susceptibility 2.6×10-9 m3/Kg Molar Magnetic Susceptibility 2.22×10-10 m3/mol Volume Magnetic Susceptibility 3.98×10-6 Abundances % in Universe 1×10-6% % in Sun 3×10-6% % in Meteorites 0.00032% % in Earth's Crust 0.006% % in Oceans 0.000012% % in Humans 0.00046% Atomic dimensions and structure Atomic Radius 265 pm Covalent Radius 220 pm Van der Waals Radius N/A Crystal Structure Body-centered Cubic Lattice Angles π/2, π/2, π/2 Lattice Constants 558.5, 558.5, 558.5 pm Space Group Name Im_ 3m Space Group Number 229 Nuclear Properties Half-Life Stable Lifetime Stable Decay Mode N/A Quantum Numbers 2S1/2 Neutron Cross Section 0.38 Neutron Mass Absorption 0.0003 Known Isotopes 71Rb, 72Rb, 73Rb, 74Rb, 75Rb, 76Rb, 77Rb, 78Rb, 79Rb, 80Rb, 81Rb, 82Rb, 83Rb, 84Rb, 85Rb, 86Rb, 87Rb, 88Rb, 89Rb, 90Rb, 91Rb, 92Rb, 93Rb, 94Rb, 95Rb, 96Rb, 97Rb, 98Rb, 99Rb, 100Rb, 101Rb, 102Rb Stable Isotopes 85Rb Isotopic Abundances 85Rb 72.17% 87Rb 27.83%