| Rubidium | |
| Electrons per shell | 2,8,18,8,1 |
| Electron Configuration | [Kr] 5s1 ![]() |
| Ground state | 2S1/2 |
| Atomic Volume | 55.9 cm3 mol-1 |
| Electronegativity | 0.82 |
| Magnetic ordering | No data |
| Mass magnetic susceptibility | 2.6 x 10-9 |
| Molar magnetic susceptibility | 2.22 x 10-10 |
| Speed of sound | 1300 m s-1 |
Thermal Properties |
|
| Enthalpy of Atomization | 82 kJ mol-1 @25°C |
| Enthalpy of Fusion | 2.2 kJ mol-1 |
| Enthalpy of Vaporisation | 75.7 kJ mol-1 |
| Heat Capacity | 31.060 J mol-1 K-1 |
| Thermal Conductivity | 58.2 W m-1 K-1 |
| Thermal Expansion | No data. |
| Critcal Temperature | 2093 K (1820°C) |
| Critcal Pressure | No data. |
| Adiabatic index | No data. |
Hardness |
|
| Brinell hardness | 0.216 MPa |
| Mohs hardness | 0.3 |
Elastic Properties |
|
| Bulk modulus | 2.5 GPa |
| Young's modulus | 2.4 GPa |
Electrical Properties |
|
| Electrical resistivity | 1.2 x 10-7 Ω m |
| Electrical conductivity | 0.0779 106/cm Ω |
Chemical Properties |
|
| Electrochemical Equivalent | 3.1888 g Ah-1 |
| Electron Work Function | 2.16 eV |
| Valence Electron Potential (-eV) | 9.47 |
| Ionization Potential | |
| 4.177 | |
| 27.28 | |
| 40 | |
Energy Levels |
|
| 13.3953 KeV | |
| 13.3358 KeV | |
| 14.9613 KeV | |
| 15.1837 KeV | |
| 14.949 KeV | |
| 1.69413 KeV | |
| 1.69256 KeV | |
| 1.75217 KeV | |
| 1.8273 KeV | |
| 1.8161 KeV | |
| 1.542 KeV | |
| 1.4829 KeV | |
Atomic Radii |
|
| 235 pm | |
| 265 pm | |
| 211 pm | |
| 244 pm | |
| No data. | |
| 248 pm | |
Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 1 | VI | 1.66 | 1.52 | |
| VII | 1.7 | 1.56 | ||
| VIII | 1.75 | 1.61 | ||
| IX | 1.77 | 1.63 | E | |
| X | 1.8 | 1.66 | C | |
| XI | 1.83 | 1.69 | C | |
| XII | 1.86 | 1.72 | C | |
| XIV | 1.97 | 1.83 | 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 |
|
| Rb-1 (in liquid NH3), Rb+1 | |
Ionisation Energies (kJ mol-1) ![]() |
|
| 403 | |
| 2632 | |
| 3900 | |
| 5080 | |
| 6850 | |
| 8140 | |
| 9570 | |
| 13100 | |
| 14800 | |
| 26740 | |
Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 434 | 486 | 552 | 641 | 769 | 958 |
Crystal Structure |
|
| Body centred cubic | |
![]() |
a = 558.5 pm |
| b = 558.5 pm | |
| c = 558.5 pm | |
| α = 90° | |
| β = 90° | |
| γ = 90° | |