Group: 17 or VII A
Atomic Weight: 18.9984032
CAS Number: 7782-41-4
No Stable Isotopes
Description • Uses/Function
In 1529, Georigius Agricola described the use of fluorspar as a flux, and as early as 1670 Schwandhard found that glass was etched when exposed to fluorspar treated with acid. Scheele and many later investigators, including Davy, Gay-Lussac, Lavoisier, and Thenard, experimented with hydrofluoric acid, some experiments ending in tragedy. The element was finally isolated in 1886 by Moisson after nearly 74 years of continuous effort. Fluorine occurs chiefly in fluorspar (CaF2) and cryolite (Na2AlF6), but is rather widely distributed in other minerals. It is a member of the halogen family of elements, and is obtained by electrolyzing a solution of potassium hydrogen fluoride in anhydrous hydrogen fluoride in a vessel of metal or transparent fluorspar. Modern commercial production methods are essentially variations on the procedures first used by Moisson. Fluorine is the most electronegative and reactive of all elements. It is a pale yellow, corrosive gas, which reacts with practically all organic and inorganic substances. Finely divided metals, glass, ceramics, carbon, and even water burn in fluorine with a bright flame.Until World War II, there was no commercial production of elemental fluorine. The atom bomb project and nuclear energy applications, however, made it necessary to produce large quantities. Safe handling techniques have now been developed and it is possible at present to transport liquid fluorine by the ton. Fluorine and its compounds are used in producing uranium (from the hexafluoride) and more than 100 commercial fluorochemicals,including many well-known high-temperature plastics. Hydrofluoric acid is extensively used for etching the glass of light bulbs, etc. Fluorochlorohydrocarbons are extensively used in air conditioning and refrigeration. It has been suggested that fluorine can be substituted for hydrogen wherever it occurs in organic compounds, which could lead to an astronomical number of new fluorine compounds. The presence of fluorine as a soluble fluoride in drinking water to the extent of 2 ppm may cause mottled enamel in teeth, when used by children acquiring permanent teeth; in smaller amounts,however, fluorides are said to be beneficial and used in water supplies to prevent dental cavities. Elemental fluorine has been studied as a rocket propellant as it has an exceptionally high specific impulse value. Compounds of fluorine with rare gases have now been confirmed. Fluorides of xenon,radon, and krypton are among those known. Elemental fluorine and the fluoride ion are highly toxic. The free element has a characteristic pungent odor, detectable in concentrations as low as 20 ppb, which is below the safe working level. The recommended maximum allowable concentration for a daily 8-hour time-weighted exposure is 1 ppm. Fluorine is known to have thirteen isotopes. 1
• "Besides its use in making atomic bombs, it is also an important element in lubricating oils especially designed for stability at all temperatures. It is also used with chlorine and other elements to form a group of compounds, often used in household refrigerators, called freons from the trade name 'Freon.'" 2
• "considered to be valuable for human health, because of its benefits to the teeth and skeleton." 3
Density:4 1.553 g/L
* - at 1 atm
Electron Configuration: [He] 2s2 2p5
Highest Occupied Energy Level: 2
Valence Electrons: 7
n = 2
ℓ = 1
mℓ = 0
ms = -½
Electronegativity (Pauling scale):5 3.98
Electropositivity (Pauling scale): 0.02
Electron Affinity:6 3.401189 eV
Oxidation States: -1
|Ionization Potential||eV 7||kJ/mol|
|Ionization Potential||eV 7||kJ/mol|
|Ionization Potential||eV 7||kJ/mol|
Specific Heat: 0.824 J/g°C 8 = 15.655 J/mol°C = 0.197 cal/g°C = 3.742 cal/mol°C
Heat of Fusion: 0.2552 kJ/mol 10 = 13.4 J/g
Heat of Vaporization: 3.2698 kJ/mol 11 = 172.1 J/g
|State of Matter||Enthalpy of Formation (ΔHf°)12||Entropy (S°)12||Gibbs Free Energy (ΔGf°)12|
|Nuclide||Mass 13||Half-Life 13||Nuclear Spin 13||Binding Energy|
|15F||15.01801(14)||410(60)E-24 s [1.0(2) MeV]||(1/2+)||97.26 MeV|
|16F||16.011466(9)||11(6)E-21 s [40(20) keV]||0-||111.85 MeV|
|17F||17.00209524(27)||64.49(16) s||5/2+||128.31 MeV|
|18F||18.0009380(6)||109.771(20) min||1+||138.24 MeV|
|20F||19.99998132(8)||11.163(8) s||2+||155.32 MeV|
|21F||20.9999490(19)||4.158(20) s||5/2+||163.39 MeV|
|22F||22.002999(13)||4.23(4) s||4+,(3+)||168.66 MeV|
|23F||23.00357(9)||2.23(14) s||(3/2,5/2)+||175.80 MeV|
|24F||24.00812(8)||400(50) ms||(1,2,3)+||179.22 MeV|
|25F||25.01210(11)||50(6) ms||(5/2+)#||183.56 MeV|
|26F||26.01962(18)||9.6(8) ms||1+||185.11 MeV|
|27F||27.02676(40)||4.9(2) ms||5/2+#||186.67 MeV|
|28F||28.03567(55)#||<40 ns||186.35 MeV|
|29F||29.04326(62)#||2.6(3) ms||5/2+#||186.97 MeV|
|30F||30.05250(64)#||<260 ns||186.66 MeV|
|31F||31.06043(64)#||1# ms [>260 ns]||5/2+#||187.28 MeV|
|Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses. 13|
Ca (s) + 1 F2 (g) → CaF2 (s) 14
I2 (s) + 2 NaF (aq) → 2 NaI (aq) + F2 (g)
P4 (s) + 6 F2 (g) → 4 PF3 (g) 15
S8 (s) + 24 F2 (g) → 8 SF6 (g) 16
SbCl3 (s) + 1 F2 (g) → SbCl3F2 (s) 17
SbF3 (s) + 1 F2 (g) → SbF5 (s) 17
UF4 (s) + 1 F2 (g) → UF6 (s) 18
2 La (s) + 3 F2 (g) → 2 LaF3 (s)
2 Dy (s) + 3 F2 (g) → 2 DyF3 (s)
Earth - Source Compounds: halide salts or brines 19
Earth - Seawater: 1.3 mg/L 20
Earth - Crust: 585 mg/kg = 0.0585% 20
Earth - Total: 13.5 ppm 21
Mercury - Total: 2.2 ppm 21
Venus - Total: 15 ppm 21
Chondrites - Total: ~700 (relative to 106 atoms of Si) 22
Human Body - Total: 0.0033% 23
aluminum fluoride trihydrate; aluminium fluoride trihydrate
aluminum fluoride; aluminium fluoride
bismuth(III) fluoride; bismuth trifluoride
cesium fluoride; caesium fluoride
chromium(II) fluoride; chromous fluoride
cobalt(II) fluoride; cobalt difluoride
dinitrogen tetrafluoride; tetrafluorohydrazine; 1,1,2,2-tetrafluorohydrazine
gallium(III) fluoride trihydrate
hydrofluoric acid; hydrogen fluoride
indium(III) fluoride trihydrate
iron(II) fluoride tetrahydrate
iron(II) fluoride; ferrous fluoride
iron(III) fluoride trihydrate
lead(II) fluoride; lead difluoride
methyl fluoride; fluoromethane*
neodymium(III) fluoride; neodymium trifluoride
oxygen difluoride; oxygen(II) fluoride
potassium aluminium fluoride; potassium tetrafluoridoaluminate; potassium tetrafluoroaluminate
titanium(III) fluoride; titanium trifluoride
uranium(VI) fluoride; uranium hexafluoride
vanadium(V) fluoride; vanadium pentafluoride
Material Safety Data Sheet - ACI Alloys, Inc.
For More Information
Chemical & Engineering News
HyperPhysics from Georgia State University's Department of Physics and Astronomy
Los Alamos National Laboratory
Physics Department of the University of Coimbra
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