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Oxidation & Electrons | Appearance & Characteristics Reactions | Compounds | Radius | Conductivity Abundance & Isotopes 
The fluoride ion, from the element fluorine, inhibits tooth decay. |
General:
| Name: Fluorine | Symbol: F |
| Type: Halogen | Atomic weight: 18.998403 |
| Density @ 293 K: 0.001696 g/cm3 | Atomic volume: 17.1 cm3/mol |
| Discovered: Georgius Agricola described the mineral fluorspar (consisting mainly of calcium fluoride) in 1530 for its use as a flux - it was added to the metals ores while they were processed in furnaces to promote fusing of the metal. The element fluorine was first isolated by Henri Moissan in 1886. Fluorine is an extremely hazardous element and earlier attempts to isolate it had lead to several blindings and fatalities. The origin of the name comes from the Latin word 'fluere', meaning to flow - hence the word flux. | |
States
| State (s, l, g): gas | |
| Melting point: 53.6 K (-219.6 oC) | Boiling point: 85.1 K (-188.1 oC) |
Energies
| Specific heat capacity: 0.82 J g-1 K-1 | Heat of atomization: 79 kJ mol-1 |
| Heat of fusion: 0.510 kJ mol-1 of F2 | Heat of vaporization (sublimation): 6.62 kJ mol-1 of F2 |
| 1st ionization energy: 1681 kJ mol-1 | 2nd ionization energy: 3374.1 kJ mol-1 |
| 3rd ionization energy: 6050.3 kJ mol-1 | Electron affinity: 328 kJ mol-1 |
Oxidation & Electrons
| Shells: 2,7 | Electron configuration: [He] 2s2 2p5 |
| Minimum oxidation number: -1 | Maximum oxidation number: 0 |
| Min. common oxidation no.: -1 | Max. common oxidation no.: 0 |
| Electronegativity (Pauling Scale): 3.98 | Polarizability volume: 0.634 Å3 |
Appearance & Characteristics
| Structure: cubic crystals in solid phase | Color: pale yellow |
| Harmful Effects: Fluorine is highly toxic and corrosive. | Hardness: mohs |
| Characteristics: Fluorine is a pale yellow, diatomic, highly corrosive, flammable gas, with a pungent odor. The lightest halogen, fluorine is also the most reactive and the most electronegative of all the elements. It reacts violently with water to produce oxygen and the extremely corrosive hydrofluoric acid. | |
| Uses: Fluorine and its compounds are used in uranium processing and in the production of fluorochemicals, including many high-temperature plastics such as Teflon. Compounds of fluorine, including sodium fluoride, are used in toothpaste and in drinking water to prevent dental cavities. Hydrofluoric acid can dissolve glass and is used to etch the glass in light bulbs and in other products. Chlorofluorocarbons (CFCs) were used in as refrigerants in air conditioning units and freezers but they have now been banned because they contribute to ozone depletion. | |
Reactions
| Reaction with air: none | Reaction with 6 M HCl: vigorous, ⇒ HF, OF2, ClF3 |
| Reaction with 3 M HNO3: ⇒ NO3F | Reaction with 6 M NaOH: vigorous, ⇒ O2, NaF |
Compounds
| Oxide(s): OF2 | Chloride(s): ClF, ClF3, ClF5 |
| Hydride(s): HF (fluoric acid) |
Radius
| Atomic radius: 50 pm | Ionic radius (1+ ion): pm |
| Ionic radius (2+ ion): pm | Ionic radius (3+ ion): pm |
| Ionic radius (2- ion): pm | Ionic radius (1- ion): 119 pm |
Conductivity
| Thermal conductivity: 0.0277 W m-1 K-1 | Electrical conductivity: S cm-1 |
Abundance & Isotopes
| Abundance earth's crust: 540 ppm by weight, 96 ppm by moles | |
| Abundance solar system: 500 parts per billion by weight, 30 parts per billion by moles | |
| Cost, pure: 190 $/100g | |
| Cost, bulk: $/100g | |
| Source: In nature, fluorine occurs mainly in the minerals fluorspar (CaF2) and cryolite (Na3AlF6). Commercially, production of fluorine involves the electrolysis of a mixture of molten potassium fluoride and hydrofluoric acid. Fluorine gas forms at the anode, and hydrogen gas at the cathode. | |
| Isotopes: Fluorine has 11 isotopes whose half-lives are known, with mass numbers 15 to 25. Of these only one is stable, 19F. | |
