| Caesium | |
| Electrons per shell | 2,8,18,18,8,1 |
| Electron Configuration | [Xe] 6s1 ![]() |
| Ground state | 2S1/2 |
| Atomic Volume | 71.07 cm3 mol-1 |
| Electronegativity | 0.79 |
| Magnetic ordering | No data |
| Mass magnetic susceptibility | -2.8 x 10-9 |
| Molar magnetic susceptibility | -3.72 x 10-10 |
Thermal Properties |
|
| Enthalpy of Atomization | 78.2 kJ mol-1 @25°C |
| Enthalpy of Fusion | 2.09 kJ mol-1 |
| Enthalpy of Vaporisation | 66.5 kJ mol-1 |
| Heat Capacity | 32.210 J mol-1 K-1 |
| Thermal Conductivity | 35.9 W m-1 K-1 |
| Thermal Expansion | 97 μm m-1 K-1 |
| Critcal Temperature | 1938 K (1665°C) |
| Critcal Pressure | No data. |
| Adiabatic index | No data. |
Hardness |
|
| Brinell hardness | 0.14 MPa |
| Mohs hardness | 0.2 |
Elastic Properties |
|
| Bulk modulus | 1.6 GPa |
| Young's modulus | 1.7 GPa |
Electrical Properties |
|
| Electrical resistivity | 2.0 x 10-7 Ω m |
| Electrical conductivity | 0.0489 106/cm Ω |
Chemical Properties |
|
| Electrochemical Equivalent | 4.9587 g Ah-1 |
| Electron Work Function | 2.14 eV |
| Valence Electron Potential (-eV) | 8.62 |
| Ionization Potential | |
| 3.894 | |
| 25.1 | |
Energy Levels |
|
| 30.9728 KeV | |
| 30.6251 KeV | |
| 34.9869 KeV | |
| 35.8152 KeV | |
| 34.9121 KeV | |
| 4.2865 KeV | |
| 4.2722 KeV | |
| 4.6198 KeV | |
| 4.9359 KeV | |
| 4.7167 KeV | |
| 4.6488 KeV | |
| 5.2804 KeV | |
| 5.5462 KeV | |
| 4.14 KeV | |
| 3.7976 KeV | |
Atomic Radii |
|
| 260 pm | |
| 298 pm | |
| 225 pm | |
| No data. | |
| No data. | |
| 265 pm | |
Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 1 | VI | 1.81 | 1.67 | |
| VIII | 1.88 | 1.74 | ||
| IX | 1.92 | 1.78 | ||
| X | 1.95 | 1.81 | ||
| XI | 1.99 | 1.85 | ||
| XII | 2.02 | 1.88 | ||
| 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 |
|
| Cs-1, Cs+1 | |
Ionisation Energies (kJ mol-1) ![]() |
|
| 375.7 | |
| 2420 | |
| 3400 | |
| 4400 | |
| 6000 | |
| 7100 | |
| 8300 | |
| 11300 | |
| 12700 | |
| 23700 | |
Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 418 | 469 | 534 | 623 | 750 | 940 |
Crystal Structure |
|
| Body centred cubic | |
![]() |
a = 614.1 pm |
| b = 614.1 pm | |
| c = 614.1 pm | |
| α = 90° | |
| β = 90° | |
| γ = 90° | |