Chlorine (Cl)

A yellow-green gas under standard conditions, highly reactive.

It was used as a chemical weapon in World War I.

Element properties

Atomic number
17
Symbol
Cl
Atomic mass
35.45 u
Category
Halogen
Period
3
Group
17
Block
p
State
Gas
Electron configuration
[Ne] 3s2 3p5
Electronegativity (Pauling)
3.16
Density
0.003214 g/cm³
Melting point
-101.5 °C
Boiling point
-34 °C

Uses