Fluorines

Fluorines refers to the fluorine element and, by extension, fluorine-containing compounds. Fluorine is the chemical element with symbol F and atomic number 9. It is the lightest halogen and exists as a pale yellow diatomic gas at room temperature. It has the highest electronegativity of all elements and a very small atomic radius, which drives its extreme reactivity. Fluorine forms compounds with almost every other element, including noble gases under certain conditions; its bonds range from highly ionic in metal fluorides to highly covalent in many organofluorine compounds.

In nature, fluorine is not found free in appreciable amounts but occurs in minerals such as fluorspar (calcium fluoride, CaF2) and cryolite; deposits are mined for industrial use. Industrial production of elemental fluorine is achieved by the electrolysis of molten salts containing fluoride, typically a mixture of potassium fluoride and hydrofluoric acid or potassium bifluoride, at high temperature. The process is highly corrosive and requires specialized materials.

Fluorine forms a wide range of fluorides including stable metal fluorides and various fluorine-containing organic compounds. One of the most important industrial materials is tetrafluoroethylene, the monomer of polytetrafluoroethylene (PTFE, Teflon). Fluorine chemistry also underpins refrigerants, pharmaceuticals, agrochemicals, and nuclear fuel processing, for example in the conversion of uranium to UF6 in enrichment.

Safety and environmental aspects: Fluorine gas is extremely reactive and toxic; contact can cause severe chemical burns and respiratory damage. Hydrofluoric acid is highly corrosive. Many fluorinated compounds are persistent in the environment and some are potent greenhouse gases or pollutants.

History: Element was isolated by Henri Moissan in 1886, who used electrolysis of potassium fluoride with hydrogen fluoride; he demonstrated elemental fluorine and won the Nobel Prize in Chemistry in 1906.