|
|
| Terbium | |
| Electron Configuration | 2,8,18,27,8,2 |
| Electron Configuration | [Xe] 4f9 6s2 |
| Ground state | 6H°15/2 |
| Atomic Volume | 19.2 g/cm3 |
| Electronegativity | 1.1 |
| Magnetic ordering | Ferromagnetic |
| Mass magnetic susceptibility | 0.0000136 |
| Molar magnetic susceptibility | 2.161385 x 10-6 |
| Speed of sound | 2620 m s-1 |
 Thermal Properties |
|
| Enthalpy of Atomization | 314 kJ mol-1 @25°C |
| Enthalpy of Fusion | 16.3 kJ mol-1 |
| Enthalpy of Vaporisation | 391 kJ mol-1 |
| Heat Capacity | 28.91 J mol-1 K-1 |
| Thermal Conductivity | 11.1 W m-1 K-1 |
| Thermal Expansion | 10.3 μm m-1 K-1 |
| Hardness |
|
| Brinell hardness | 677 MPa |
| Vickers hardness | 863 MPa |
| Elastic Properties |
|
| Bulk modulus | 38.7 GPa |
| Poisson ratio | 0.261 |
| Shear modulus | 22.1 GPa |
| Young's modulus | 55.7 GPa |
| Electrical Properties |
|
| Electrical resistivity | 1.20 x 10-6 Ω m |
| Electrical conductivity | No data. |
| Chemical Properties |
|
| Electrochemical Equivalent | 1.9765 g Ah-1 |
| Electron Work Function | 3 eV |
| Valence Electron Potential (-eV) | 46.8 |
| Ionization Potential | |
 First
|
5.86 |
| Second
|
11.525 |
| Third
|
21.91 |
| Energy Levels |
|
| Kα1 (intensity 100) |
44.4816 KeV |
| Kα2 (intensity 50) |
43.7441 KeV |
| Kβ1 (intensity 23.2) |
50.382 KeV |
| Kβ2 (intensity 8.3) |
51.6074 KeV |
| Kβ3 (intensity 9.4) |
50.2341 KeV |
| Lα1 (intensity 100) |
6.2728 KeV |
| Lα2 (intensity 10) |
6.238 KeV |
| Lβ1 (intensity 45) |
6.978 KeV |
| Lβ2 (intensity 17) |
7.3667 KeV |
| Lβ3 (intensity 10) |
7.0965 KeV |
| Lβ4 (intensity 4) |
6.941 KeV |
| Lγ1 (intensity 6) |
8.102 KeV |
| Lγ2 (intensity 2) |
8.3908 KeV |
| Lγ3 (intensity 2) |
6.282 KeV |
| Ll (intensity 4.5) |
5.5521 KeV |
| Atomic Radii |
|
| Empirical
|
175 pm |
| Bohr Radius
|
225 pm |
| Covalent Radius
|
No data. |
| Van der Waals
|
No data. |
| Triple covalent
|
No data. |
| Metallic
|
177.3 pm |
| Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 3 | VI | 1.063 | 0.923 | R |
| VII | 1.12 | 0.98 | E | |
| VIII | 1.18 | 1.04 | R | |
| IX | 1.235 | 1.095 | R | |
| 4 | VI | 0.9 | 0.76 | R |
| VIII | 1.02 | 0.88 | ||
| 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
|
Tb+3 |
| Other
|
Tb+4 |
Ionisation Energies (kJ mol-1)  |
|
| M - M+ |
564.6 |
| M+ - M2+ |
1112 |
| M2+ - M3+ |
2114 |
| M3+ - M4+ |
3839 |
| Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 1789 | 1979 | (2201) | (2505) | (2913) | (3491) |
| Crystal Structure |
|
| Structure
|
Hexagonal close packed |
 |
a = 360.1 pm |
| b = 360.1 pm | |
| c = 569.36 pm | |
| α = 90° | |
| β = 90° | |
| γ = 120° | |