Element overview
Chlorine (Cl) is element 17 with a listed atomic mass of 35.45 u. It is in group 17 and period 3. Its category is halogen.
Atomic properties
Electron configuration: [Ne] 3s2 3p5. Electronegativity: 3.16. Common oxidation states: -1, +1, +3, +5, +7.
Physical properties
Density: 0.003214; melting point: 171.6; boiling point: 239.11. Values depend on conditions, phase and source.