Lanthanum

Symbol | La
Latin name | Lanthanium
Atomic number | 57
Period | 6
Element category | Transition elements
Relative atomic mass | 138.9055
Group | III.B
Electronegativity | 1.1
Oxidation numbers | 3
Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 5d1 6s2
Density [g/cm3] | 6.166
State | Solid
Melting point [°C] | 921
Boiling point [°C] | 3457
Covalent radius [pm] | 169
Thermal conductivity [W m-1K-1] | 13.5
Heat capacity [J K-1g-1] | 0.19
Discovery | 1839
Hardness [Mohs scale] | 2.5
Vickers hardness [MPa] | 491
Brinell hardness [MPa] | 363
Young's modulus [GPa] | 37
Electrical conductivity [S m-1] | 1.9 · 106
Shear modulus [GPa] | 14
1.st ionization energy [eV] | 5.577
2.nd ionization energy [eV] | 11.059
3.rd ionization energy [eV] | 19.174
Stable isotopes | 2
Unstable isotopes | 16