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Fluorine is a chemical element; it has symbol F and atomic number 9. It is the lightest halogen [note 1] and exists at standard conditions as pale yellow diatomic gas. Fluorine is extremely reactive as it reacts with all other elements except for the light inert gases. It is highly toxic.
Substituting a fluorine into a para position, however, protects the aromatic ring and prevents the epoxide from being produced. [13] Adding fluorine to biologically active organic compounds increases their lipophilicity (ability to dissolve in fats), because the carbon–fluorine bond is even more hydrophobic than the carbon–hydrogen bond.
Moissan's fluorine cell, from his 1887 publication. Fluorine is a relatively new element in human applications. In ancient times, only minor uses of fluorine-containing minerals existed. The industrial use of fluorite, fluorine's source mineral, was first described by early scientist Georgius Agricola in the 16th century, in the context of ...
Fluorine is an important element for biological systems. From a mammalian health perspective, it is notable as a component of fluorapatite , a key mineral in the teeth of humans that have been exposed to fluorine, as well as shark and fish teeth. [ 4 ]
And any created fluorine within stars is rapidly eliminated through strong nuclear fusion reactions—either with hydrogen to form oxygen and helium, or with helium to make neon and hydrogen. [ 2 ] [ 3 ] The presence of fluorine at all—outside of temporary existence in stars—is somewhat of a mystery because of the need to escape these ...
Charles Betts, a prominent anti-fluoridationist, charged that fluoridation was "better than using the atom bomb because the atom bomb has to be made, has to be transported to the place it is to be set off while poisonous fluorine has been placed right beside the water supplies by the Americans themselves ready to be dumped into the water mains ...
Fluorine has the lowest polarizability of all atoms: 0.56 10 −24 cm 3. [1] This causes very weak dispersion forces between polyfluorinated molecules and is the reason for the often-observed boiling point reduction on fluorination as well as for the simultaneous hydrophobicity and lipophobicity of polyfluorinated compounds whereas other ...
The fluorine–fluorine bond of the difluorine molecule is relatively weak when compared to the bonds of heavier dihalogen molecules. The bond energy is significantly weaker than those of Cl 2 or Br 2 molecules and similar to the easily cleaved oxygen–oxygen bonds of peroxides or nitrogen–nitrogen bonds of hydrazines. [8]