Technical data for Rubidium

Overview
NameRubidium
SymbolRb
Atomic Number37
Atomic Weight85.4678
Density1.532 g/cm3
Melting Point39.31 °C
Boiling Point688 °C

Thermal properties
PhaseSolid
Melting Point39.31 °C
Boiling Point688 °C
Absolute Melting Point312.46 K
Absolute Boiling Point961 K
Critical Presure16 MPa (157.9 Atm)[note]
Critical Temperature2093 K[note]
Heat of Fusion2.19 kJ/mol
Heat of Vaporization72 kJ/mol
Heat of CombustionN/A
Specific Heat364 J/(kg K)[note]
Thermal Conductivity58 W/(m K)
Thermal ExpansionN/A

Bulk physical properties
Density1.532 g/cm3
Density (Liquid)1.46 g/cm3
Molar Volume0.000055788
Brinell Hardness0.216 MPa
Mohs Hardness0.3 MPa
Bulk Modulus2.5 GPa
Young Modulus2.4 GPa
Speed of Sound1.3×103 m/s
Thermal Conductivity58 W/(m K)
Thermal ExpansionN/A

Reactivity
Valence1
Electronegativity0.82
ElectronAffinity46.9 kJ/mol
Ionization Energies
403, 2633, 3860, 5080, 6850, 8140, 9570, 13120, 1.45×104, 26740 kJ/mol

Health and Safety
Autoignition PointN/A
FlashpointN/A

Classifications
Alternate NamesNone
Nams of AllotropesNone
Blocks
Group1
Period5
Electron Configuration[Kr]5s1
ColorSilver
Discovery
1861 in Germany
Gas phaseN/A
CAS NumberCAS7440-17-7

Electrical properties
Electrical TypeConductor
Electrical Conductivity8.3×106 S/m
Resistivity1.2×10-7 m Ω
Superconducting PointN/A

Magnetic properties
Magnetic TypeN/A
Mass Magnetic Susceptibility2.6×10-9
Molar Magnetic Susceptibility2.22×10-10
Volume Magnetic Susceptibility3.98×10-6

Abundances
% in Universe1×10-6%
% in Sun3×10-6%
% in Meteorites0.00032%
% in Earth's Crust0.006%
% in Oceans0.000012%
% in Humans0.00046%

Atomic dimensions and structure
Atomic Radius265 pm
Covalent Radius211 pm
Van der Waals RadiusN/A
Crystal StructureBody Centered Cubic
Lattice Angles
π/2, π/2, π/2
Lattice Constants
558.5, 558.5, 558.5 pm
Space Group NameIm_ 3m
Space Group Number229

Nuclear Properties
Half-LifeStable
LifetimeStable
Stable Isotopes
85Rb
Isotopic Abundances
85Rb72.17%
87Rb27.83%

Notes on the properties of Rubidium:
Critical Pressure: Value estimated based on extrapolation.
Critical Temperature: Value estimated based on extrapolation.
Specific Heat: Value given for solid phase.