| Element | Cesium | Symbol | Cs |
| Atomic Number | 55 | Molar Mass | 132.91 gmol-1 |
| Electron Configuration | [Xe]6s1 | Normal State | solid metal |
| Density @STP | 1.87 g cm-3 | Melting Point | 28.4oC |
| Boiling Point | 671oC | Stable Isotopes | 133Cs |
| Atomic Radius | 272 pm | Ionic Radius | 170 (1+) pm |
| Electronegativity (Pauling) | 0.79 | Ionization Energy (1st) | 376 kJ mol-1 |
| Ionization Energy (2nd) | 2420 kJ mol-1 | Ionization Energy (3rd) | 3400 kJ mol-1 |
| Molar Heat Capacity | 32.2 J K-1mol-1 | Standard Molar Entropy | 85.2 J K-1mol-1 |
| Enthalpy of Fusion | 2.09 kJ mol-1 | Enthalpy of Vapourization | 65.9 kJ mol-1 |