Technical data for Thulium

Overview
NameThulium
SymbolTm
Atomic Number69
Atomic Weight168.93421
Density9.321 g/cm3
Melting Point1545 °C
Boiling Point1950 °C

Thermal properties
PhaseSolid
Melting Point1545 °C
Boiling Point1950 °C
Absolute Melting Point1818 K
Absolute Boiling Point2223 K
Heat of Fusion16.8 kJ/mol
Heat of Vaporization250 kJ/mol
Heat of CombustionN/A
Specific Heat160 J/(kg K)[note]
Neel Point56 K
Thermal Conductivity17 W/(m K)
Thermal Expansion0.0000133 K-1

Bulk physical properties
Density9.321 g/cm3
Density (Liquid)8.56 g/cm3
Molar Volume0.000018124
Brinell Hardness471 MPa
Vickers Hardness520 MPa
Bulk Modulus45 GPa
Shear Modulus31 GPa
Young Modulus74 GPa
Poisson Ratio0.21
Thermal Conductivity17 W/(m K)
Thermal Expansion0.0000133 K-1

Reactivity
Valence3
Electronegativity1.25
ElectronAffinity50 kJ/mol
Ionization Energies
596.7, 1160, 2285, 4120 kJ/mol

Health and Safety
Autoignition PointN/A
FlashpointN/A

Classifications
Alternate NamesNone
Nams of AllotropesNone
Blockf
GroupN/A
Period6
Electron Configuration[Xe]4f136s2
ColorSilver
Discovery
1879 in Sweden
Gas phaseN/A
CAS NumberCAS7440-30-4

Electrical properties
Electrical TypeConductor
Electrical Conductivity1.4×106 S/m
Resistivity7×10-7 m Ω
Superconducting PointN/A

Magnetic properties
Magnetic TypeParamagnetic
Curie Point25 K
Mass Magnetic Susceptibility1.99×10-6
Molar Magnetic Susceptibility3.36179×10-7
Volume Magnetic Susceptibility0.0185488

Abundances
% in Universe1×10-8%
% in Sun2×10-8%
% in Meteorites2.9×10-6%
% in Earth's Crust0.000045%
% in Oceans2×10-11%
% in HumansN/A

Atomic dimensions and structure
Atomic Radius222 pm
Covalent RadiusN/A
Van der Waals RadiusN/A
Crystal StructureSimple Hexagonal
Lattice Angles
π/2, π/2, 2 π/3
Lattice Constants
353.75, 353.75, 555.46 pm
Space Group NameP63/mmc
Space Group Number194

Nuclear Properties
Half-LifeStable
LifetimeStable
Stable Isotopes
169Tm
Isotopic Abundances
169Tm100%

Notes on the properties of Thulium:
Specific Heat: Value given for solid phase.