SymbolEr
Latin nameErbium
Atomic number68
Period6
Element categoryInner transition elements
Relative atomic mass167.26
GroupIII.B
Electronegativity
1.2
Oxidation numbers
3
Electron configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f12 5d0 6s2
Density [g/cm3]
9.066
State
Solid
Melting point [°C]
1545
Boiling point [°C]
2863
Atomic radius [pm]
226
Thermal conductivity [W m-1K-1]
14.3
Heat capacity [J K-1g-1]
0.168
Discovery
1843
Vickers hardness [MPa]
589
Brinell hardness [MPa]
814
Young's modulus [GPa]
70
Electrical conductivity [S m-1]
1.2 · 106
Shear modulus [GPa]
28
1.st ionization energy [eV]
6.1078
2.nd ionization energy [eV]
11.929
3.rd ionization energy [eV]
22.739
Stable isotopes
6
Unstable isotopes
10