Fluorine

Fluorine is a chemical element wi seembol F an atomic nummer 9. It is the lichtest halogen an exists as a heichly toxic pale yellae diatomic gas at staundary condeetions. As the maist electronegative element, it is extremely reactive: awmaist aw ither elements, includin some noble gases, form compoonds wi fluorine.

Fluorine, ₉F

Liquid fluorine (at extremely law temperaturs)
Fluorine
Pronunciation	/ˈflʊəriːn, -ɪn/ (FLOOR-een, -in) /ˈflɔːriːn, -ɪn/ (FLOR-een, -in)
Appearance	gas: vera fauch yellae liquid: bricht yellae solid: skyre (beta), opaque (alpha)
Standard atomic weight Ar, std(F)	7001189984031630000♠18.998403163(6)
Fluorine in the periodic cairt
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gowd Mercur (element) Thallium Leid (element) Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium - ↑ F ↓ Cl oxygen ← fluorine → neon
Atomic nummer (Z)	9
Group	group 17 (halogens)
Period	period 2
Block	p-block
Element category	Reactive nonmetal
Electron confeeguration	[He] 2s2 2p5
Electrons per shell	2, 7
Pheesical properties
Phase at STP	gas
Meltin pynt	53.48 K ​(−219.67 °C, ​−363.41 °F)
Bylin pynt	85.03 K ​(−188.11 °C, ​−306.60 °F)
Density (at STP)	1.696 g/L
whan liquid (at b.p.)	1.505 g/cm3
Treeple pynt	53.48 K, ​90 kPa
Creetical pynt	144.41 K, 5.1724 MPa
Heat o vapourisation	6.51 kJ/mol
Molar heat capacity	(Cp) (21.1 °C) 31 J·mol−1·K−1 (Cv) (21.1 °C) 23 J/(mol·K)
Vapour pressur P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 38 44 50 58 69 85
Atomic properties
Oxidation states	−1 (oxidizes oxygen)
Electronegativity	Pauling scale: 3.98
Ionisation energies	(more)
Covalent radius	64 pm
Van der Waals radius	135 pm
Colour lines in a spectral range Spectral lines o fluorine
Ither properties
Naitural occurrence	primordial
Creestal structur	​base-centred monoclinic alpha state (low-temperature)
Thermal conductivity	0.02591 W/(m·K)
Magnetic orderin	diamagnetic, −1.2×10−4 (SI)
CAS Nummer	7782-41-4
History
Namin	efter the mineral fluorite, itsel named efter Latin fluo (taur pirr, in smeltin)
Diskivery	André-Marie Ampère (1810)
First isolation	Henri Moissan (Juin 26, 1886)
Named by	Humphry Davy
Main isotopes o fluorine
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct 18F trace 109.77 min β+ (96.9%) 18O ε (3.1%) 18O 19F 100% stable
reference

Amang the elements, fluorine ranks 24t in universal abundance an 13t in terrestrial abundance. Fluorite, the primar mineral soorce o fluorine which gae the element its name, wis first descrived in 1529; as it wis addit tae metal ures tae lawer thair meltin pynts for smeltin, the Laitin verb fluo meanin "flowe" gae the mineral its name. Proponed as an element in 1810, fluorine pruived difficult an dangerous tae separate frae its compoonds, an several early experimenters dee'd or susteened injuries frae thair attempts. Anerly in 1886 did French chemist Henri Moissan isolate elemental fluorine uisin law-temperatur electrolysis, a process still employed for modren production. Industrial production o fluorine gas for uranium enrichment, its lairgest application, began in the Manhattan Project in Warld War II.

Awin tae the expense o refinin pure fluorine, maist commercial applications uise fluorine compoonds, wi aboot hauf o mined fluorite uised in steelmakkin. The rest o the fluorite is convertit intae corrosive hydrogen fluoride en route tae various organic fluorides, or intae cryolite which plays a key role in aluminium refinin. Organic fluorides hae very heich chemical an thermal stability; thair major uises are as refrigerants, electrical insulation an cuikware, the last as PTFE (Teflon). Pharmaceuticals sic as atorvastatin an fluoxetine an aa contain fluorine, an the fluoride ion inhibits dental cavities, an sae finds uise in toothpaste an watter fluoridation. Global fluorochemical sales amount tae mair nor US$15 billion a year.

Fluorocarbon gases are generally greenhoose gases wi global-wairmin potentials 100 tae 20,000 times that o carbon dioxide. Organofluorine compoonds persist in the environment due tae the strenth o the carbon–fluorine bond. Fluorine haes na kent metabolic role in mammals; a few plants synthesize organofluorine pushions that deter yerbivores.