Thulium

Symbol | Tm
Latin name | Thulium
Atomic number | 69
Period | 6
Element category | Inner transition elements
Relative atomic mass | 168.93421
Group | III.B
Electronegativity | 1.2
Oxidation numbers | 2, 3
Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f13 5d0 6s2
Density [g/cm3] | 9.318
State | Solid
Melting point [°C] | 1545
Boiling point [°C] | 1947
Atomic radius [pm] | 222
Thermal conductivity [W m-1K-1] | 16.8
Heat capacity [J K-1g-1] | 0.16
Discovery | 1879
Vickers hardness [MPa] | 520
Brinell hardness [MPa] | 471
Young's modulus [GPa] | 74
Electrical conductivity [S m-1] | 1.4 · 106
Shear modulus [GPa] | 31
1.st ionization energy [eV] | 6.1843
2.nd ionization energy [eV] | 12.054
3.rd ionization energy [eV] | 26.367
Stable isotopes | 1
Unstable isotopes | 17