Fluorine was the chemical element first isolated by Henri Moissan in 1886.
Fluorine has atomic number 9 and symbol F. It is the lightest halogen and the most reactive of the halogen elements, so it was exceptionally difficult to isolate. Earlier chemists had recognized that hydrofluoric acid contained an unknown element, but attempts to separate it often produced dangerous reactions and serious injuries.
French chemist Henri Moissan succeeded by electrolyzing a mixture of potassium hydrogen fluoride and anhydrous hydrogen fluoride in a specially designed apparatus. He obtained fluorine gas on June 26, 1886. Moissan received the 1906 Nobel Prize in Chemistry for his work on fluorine and the electric furnace.
Fluorine is not normally found as a free element in nature because it reacts so readily. Fluoride ions occur in minerals such as fluorite, while fluorine compounds are used in areas including chemical manufacturing, refrigeration, and dental care.