| Element | Potassium | Symbol | K |
| Atomic Number | 19 | Molar Mass | 39.1 gmol-1 |
| Electron Configuration | [Ar]4s1 | Normal State | solid metal |
| Density @STP | 0.86 g cm-3 | Melting Point | 63oC |
| Boiling Point | 759oC | Stable Isotopes | 39K, 40K, 41K |
| Atomic Radius | 235 pm | Ionic Radius | 138 (1+) pm |
| Electronegativity (Pauling) | 0.82 | Ionization Energy (1st) | 419 kJ mol-1 |
| Ionization Energy (2nd) | 3051 kJ mol-1 | Ionization Energy (3rd) | 4411 kJ mol-1 |
| Molar Heat Capacity | 29.6 J K-1mol-1 | Standard Molar Entropy | 64.7 J K-1mol-1 |
| Enthalpy of Fusion | 2.4 kJ mol-1 | Enthalpy of Vapourization | 77.53 kJ mol-1 |