|
|
| Praseodymium | |
| Electron Configuration | 2,8,18,21,8,2 |
| Electron Configuration | [Xe] 4f3 6s2 |
| Ground state | 4I°9/2 |
| Atomic Volume | 20.8 g/cm3 |
| Electronegativity | 1.13 |
| Magnetic ordering | No data |
| Mass magnetic susceptibility | 4.23 x 10-7 |
| Molar magnetic susceptibility | 5.9604 x 10-8 |
| Speed of sound | 2280 m s-1 |
 Thermal Properties |
|
| Enthalpy of Atomization | 368 kJ mol-1 @25°C |
| Enthalpy of Fusion | 11.3 kJ mol-1 |
| Enthalpy of Vaporisation | 357 kJ mol-1 |
| Heat Capacity | 27.20 J mol-1 K-1 |
| Thermal Conductivity | 12.5 W m-1 K-1 |
| Thermal Expansion | 6.7 μm m-1 K-1 |
| Hardness |
|
| Brinell hardness | 481 MPa |
| Vickers hardness | 400 MPa |
| Elastic Properties |
|
| Bulk modulus | 28.8 GPa |
| Poisson ratio | 0.281 |
| Shear modulus | 14.8 GPa |
| Young's modulus | 37.3 GPa |
| Electrical Properties |
|
| Electrical resistivity | 7.0 x 10-7 Ω m |
| Electrical conductivity | No data. |
| Chemical Properties |
|
| Electrochemical Equivalent | 1.7524 g Ah-1 |
| Electron Work Function | 2.7 eV |
| Valence Electron Potential (-eV) | 42.64 |
| Ionization Potential | |
 First
|
5.46 |
| Second
|
10.551 |
| Third
|
21.62 |
| Energy Levels |
|
| Kα1 (intensity 100) |
36.0263 KeV |
| Kα2 (intensity 50) |
35.5502 KeV |
| Kβ1 (intensity 21.6) |
40.7482 KeV |
| Kβ2 (intensity 7.1) |
41.7557 KeV |
| Kβ3 (intensity 9.1) |
40.6435 KeV |
| Lα1 (intensity 100) |
5.0337 KeV |
| Lα2 (intensity 10) |
5.0135 KeV |
| Lβ1 (intensity 52) |
5.4889 KeV |
| Lβ2 (intensity 22) |
5.85 KeV |
| Lβ3 (intensity 12) |
5.5943 KeV |
| Lβ4 (intensity 4) |
5.4977 KeV |
| Lγ1 (intensity 5.5) |
6.3221 KeV |
| Lγ2 (intensity 1.5) |
6.5998 KeV |
| Lγ3 (intensity 2) |
4.934 KeV |
| Ll (intensity 3.5) |
4.4614 KeV |
| Atomic Radii |
|
| Empirical
|
185 pm |
| Bohr Radius
|
247 pm |
| Covalent Radius
|
No data. |
| Van der Waals
|
No data. |
| Triple covalent
|
128 pm |
| Metallic
|
182.4 pm |
| Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 3 | VI | 1.13 | 0.99 | R |
| VIII | 1.266 | 1.126 | R | |
| IX | 1.319 | 1.179 | R | |
| 4 | VI | 0.99 | 0.85 | R |
| VIII | 1.1 | 0.96 | R | |
| 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 |
|
| Main
|
Pr+3 |
| Other
|
Pr+4 |
Ionisation Energies (kJ mol-1)  |
|
| M - M+ |
523.1 |
| M+ - M2+ |
1018 |
| M2+ - M3+ |
2086 |
| M3+ - M4+ |
3761 |
| M4+ - M5+ |
5543 |
| Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 1771 | 1973 | (2227) | (2571) | (3054) | (3779) |
| Crystal Structure |
|
| Structure
|
Hexagonal close packed |
 |
a = 367.25 pm |
| b = 367.25 pm | |
| c = 1183.54 pm | |
| α = 90° | |
| β = 90° | |
| γ = 120° | |