Industrial production of fluorine gas for uranium enrichment, its largest application, began during the Manhattan Project in World War II. Owing to the expense of refining pure fluorine, most commercial applications use fluorine compounds, with about half of mined fluorite used in steelmaking. It is highly corrosive and is used to separate certain isotopes of uranium and to make refrigerants and high-temperature plastics.It is also added in fluoride form to the water supply to prevent tooth decay.Alkali metals cause explosions and alkaline earth metals display vigorous activity in bulk; to prevent passivation from the formation of metal fluoride layers, most other metals such as aluminium and iron must be powdered, Carbon, as lamp black, reacts at room temperature to yield fluoromethane. Graphite combines with fluorine above 400 °C (750 °F) to produce non-stoichiometric carbon monofluoride; higher temperatures generate gaseous fluorocarbons, sometimes with explosions. a toxic pungent pale yellow gas of the halogen group that is the most electronegative and reactive of all the elements, occurring principally in fluorspar and cryolite: used in the production of uranium, fluorocarbons, and other chemicals.
Global fluorochemical sales amount to more than US billion a year.
Although nitrogen trifluoride is stable, nitrogen requires an electric discharge at elevated temperatures for reaction with fluorine to occur, due to the very strong triple bond in elemental nitrogen; Oxygen does not combine with fluorine under ambient conditions, but can be made to react using electric discharge at low temperatures and pressures; the products tend to disintegrate into their constituent elements when heated. The latter crystallizes at −220 °C (−364 °F) and is transparent and soft, with the same disordered cubic structure of freshly crystallized solid oxygen, Further cooling to −228 °C (−378 °F) induces a phase transition into opaque and hard α-fluorine, which has a monoclinic structure with dense, angled layers of molecules.
The transition from β- to α-fluorine is more exothermic than the condensation of fluorine, and can be violent.
Fluorocarbon gases are generally greenhouse gases with global-warming potentials 100 to 20,000 times that of carbon dioxide.
Organofluorine compounds persist in the environment due to the strength of the carbon–fluorine bond. E.; Revés, M.; Echeverría, J.; Cremades, E.; Barragán, F.; Alvarez, S.