Atomic Number: 9
Atomic Symbol: F
Atomic Weight: 18.9984032
Melting Point: -363.41 F (-219.67 C)
Boiling Point: -370.62 F (-188.12 C)

Word origin: From the Latin and French word fluere, meaning flow or flux.

Discovery: Georigius Agricola described the use of fluorspar as a flux in 1529, and as early as 1670 Schwandhard found that glass was etched when exposed to fluorspar treated with acid. Carl Wilhelm Scheele and many other scientists experimented with hydrofluoric acid, with some experiments ending in tragedy. Ferdinand Frederick Henri Moissan, a French chemist, finally isolated the element in 1866.

Fluorite crystal
Fluorite crystal
Credit: Gala_Kan Shutterstock

Properties of fluorine

Fluorine is found in nature in the form of calcium fluoride, called fluorite, which forms regular crystals. California has many fluorite deposits. There are also deposits in Alaska and Argentina

Fluorine is the most electronegative and reactive of all elements. [See Periodic Table of the Elements]

Fluorine gas is a pale yellow, corrosive gas, which reacts with most organic and inorganic substances. Finely divided metals, glass, ceramics, carbon, and even water burn in fluorine with a bright flame.

Compounds of fluorine with rare gases have now been confirmed in fluorides of xenon, krypton and radon. One hypothesis says that fluorine can be substituted for hydrogen wherever it occurs in organic compounds, which could lead to a massive number of new fluorine compounds.

Fluorine can be transported by the ton safely when properly handling techniques are followed.

Uses of fluorine

Until World War II, there was no commercial production of elemental fluorine. The nuclear bomb project and nuclear energy applications, however, made it necessary to produce large quantities.

Fluorine and its compounds are used in producing uranium (from the hexafluoride) and more than 100 commercial fluorochemicals, including many high-temperature plastics. Hydrofluoric acid is used to etch light bulbs and other glass. Fluorochlorohydrocarbons are extensively used in air conditioning and refrigeration.

Flourine as a soluble fluoride in drinking water can help prevent dental cavities, but at 2 ppm it may cause mottled enamel in teeth when used by children acquiring permanent teeth.

Elemental fluorine has been studied as a rocket propellant as it has an exceptionally high specific impulse value.

(Source: Los Alamos National Laboratory)