| name | Chlorine |
| latin | Chlorum |
| french | Chlore |
| german | Chlor |
| symbol | Cl |
| proton number | 17 |
| atomic weight | 35.4527 |
| Pauling electronegativity | 3.16 |
| electronic configuration | [Ne] 3s23p5 1s22s22p63s23p5 |
| melting point | 171.6 K, -101.55°C, -150.79°F |
| boiling point | 239.11 K, -34.04°C, -29.27°F |
| group | 17 |
| period | 3 |
| state (by 20°C) | gas |
| oxidation states | -1, +1, +3, +5, +7 |
| Year of discovery | Discoverer |
| 1774 | Carl Wilhelm Scheele (1742-1786) |