| Lanthanum | |
| Electrons per shell | 2,8,18,18,9,2 |
| Electron Configuration | [Xe] 5d1 6s2 ![]() |
| Ground state | 2D3/2 |
| Atomic Volume | 20.73 cm3 mol-1 |
| Electronegativity | 1.1 |
| Magnetic ordering | No data |
| Mass magnetic susceptibility | 1.1 x 10-8 |
| Molar magnetic susceptibility | 1.528 x 10-9 |
| Speed of sound | 2475 m s-1 |
Thermal Properties |
|
| Enthalpy of Atomization | 431 kJ mol-1 @25°C |
| Enthalpy of Fusion | 10.04 kJ mol-1 |
| Enthalpy of Vaporisation | 402.1 kJ mol-1 |
| Heat Capacity | 27.11 J mol-1 K-1 |
| Thermal Conductivity | 13.4 W m-1 K-1 |
| Thermal Expansion | 12.1 μm m-1 K-1 |
| Critcal Temperature | No data. |
| Critcal Pressure | No data. |
| Adiabatic index | No data. |
Hardness |
|
| Brinell hardness | 363 MPa |
| Mohs hardness | 2.5 |
| Vickers hardness | 491 MPa |
Elastic Properties |
|
| Bulk modulus | 27.9 GPa |
| Poisson ratio | 0.280 |
| Shear modulus | 14.3 GPa |
| Young's modulus | 36.6 GPa |
Electrical Properties |
|
| Electrical resistivity | 6.1 x 10-7 Ω m |
| Electrical conductivity | 0.0126 106/cm Ω |
Chemical Properties |
|
| Electrochemical Equivalent | 1.7275 g Ah-1 |
| Electron Work Function | 3.5 eV |
| Valence Electron Potential (-eV) | 40.71 |
| Ionization Potential | |
| 5.58 | |
| 11.059 | |
| 19.174 | |
Energy Levels |
|
| 33.4418 KeV | |
| 33.0341 KeV | |
| 37.801 KeV | |
| 38.7215 KeV | |
| 37.7144 KeV | |
| 4.65097 KeV | |
| 4.63423 KeV | |
| 5.0421 KeV | |
| 5.3835 KeV | |
| 5.1436 KeV | |
| 5.0623 KeV | |
| 5.7885 KeV | |
| 6.0595 KeV | |
| 4.523 KeV | |
| 4.123 KeV | |
Atomic Radii |
|
| 195 pm | |
| No data. | |
| 169 pm | |
| No data. | |
| 139 pm | |
| 187 pm | |
Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 3 | VI | 1.172 | 1.032 | R |
| VII | 1.24 | 1.1 | ||
| VIII | 1.3 | 1.16 | R | |
| IX | 1.356 | 1.216 | R | |
| X | 1.41 | 1.27 | ||
| XII | 1.5 | 1.36 | C | |
| R, From r3 vs V plots. |
| C, Calculated from bond length - bond strength equations. |
| E, Estimated. |
| *, Most Reliable. |
| M, From Metallic Oxides. |
| A, Ahrens (1952) Ionic radius. |
| P, Pauling's (1960) Crystal Radius. |
Oxidation States |
|
| La+3 | |
Ionisation Energies (kJ mol-1) ![]() |
|
| 538.1 | |
| 1067 | |
| 1850 | |
| 4819 | |
| 6400 | |
| 7600 | |
| 9600 | |
| 11000 | |
| 12400 | |
| 15900 | |
Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 2005 | 2208 | 2458 | 2772 | 3178 | 3726 |
Crystal Structure |
|
| Hexagonal close packed | |
![]() |
a = 377.2 pm |
| b = 377.2 pm | |
| c = 1214.4 pm | |
| α = 90° | |
| β = 90° | |
| γ = 120° | |