17
Cl
Chlorine
halogen
Discovered : Carl Wilhelm Scheele, 1774. Identified as an element by Humphry Davy in 1810.
Found in : Halite (NaCl), sylvite (KCl), atacamite, chlorargyrite.
Used for : Water purification, PVC plastics, bleach, pharmaceutical synthesis.
Remarkable : Cannot exist freely in nature for long. As chlorine gas it was used as a chemical weapon in World War I. As chloride ion in salt, it is essential to all life and to the transmission of nerve impulses.
Minerals containing Chlorine
