Properties

Atomic Number	17
CAS Registry Number	7782-50-5
Chemical Symbol	Cl

History

The atomic number is 17 and the chemical symbol is Cl. The name derives from the Greek chlooros for pale green or greenish yellow color of the element. It was discovered by the Swedish pharmacist and chemist Carl-Wilhelm Scheele in 1774. In 1810 the English chemist Humphry Davy proved it was an element and gave it the name chlorine.

Holden, Norman E., (2004). History of the origin of the chemical elements and their discoverers. National Nuclear Data Center. Retrieved from http://www.nndc.bnl.gov/content/elements.html