| Element | Chlorine | Symbol | Cl |
| Atomic Number | 17 | Molar Mass | 35.45 gmol-1 |
| Electron Configuration | [Ne]3s23p5 | Normal State | gas nonmetal |
| Density @STP | 3.21x10-3 g cm-3 | Melting Point | -101oC |
| Boiling Point | -34oC | Stable Isotopes | 35Cl, 37Cl |
| Atomic Radius | 99 pm | Ionic Radius | 181 (1-) pm |
| Electronegativity (Pauling) | 3.16 | Ionization Energy (1st) | 1251 kJ mol-1 |
| Ionization Energy (2nd) | 2297 kJ mol-1 | Ionization Energy (3rd) | 3826 kJ mol-1 |
| Molar Heat Capacity | 21.8 J K-1mol-1 | Standard Molar Entropy | 165.2 J K-1mol-1 |
| Enthalpy of Fusion | 6.41 kJ mol-1 | Enthalpy of Vapourization | 20.4 kJ mol-1 |