Chlorine, with the chemical symbol Cl, is an extremely reactive halogen and an essential element for life. It was first isolated in the 18th century by the Swedish chemist Carl Wilhelm Scheele and further studied by Sir Humphry Davy. Chlorine is not found in its elemental form on Earth but typically exists in compounds, most commonly as chloride in salts.
Chlorine ranks as the 21st most abundant element in the Earth's crust, constituting about 0.02% of the Earth's crust. It plays a crucial role in biological processes and is an essential component of sodium chloride, which is vital for the proper functioning of the human body.
Exciting applications of chlorine span from water and pool disinfection to the production of plastics like PVC. In the future, advanced applications in hydrogen production and energy storage could emerge through the utilization of chlorine compounds.