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 |