Search results
Results From The WOW.Com Content Network
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.
The mineral also has a dark black color, perhaps from free calcium (not bonded to fluoride). In 2012, a study reported detection of trace quantities (0.04% by weight) of diatomic fluorine in antozonite. It was suggested that radiation from small amounts of uranium within the crystals had caused the free fluorine defects. [16]
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 ...
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.
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]
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]
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 ...
In 1949 Simons and his coworkers published a long paper in the Journal of the Electrochemical Society. [3] The Simons process is used for the production of perfluorinated amines, ethers, carboxylic acids, and sulfonic acids. For carboxylic and sulfonic acids, the products are the corresponding acyl fluorides and sulfonyl fluorides. The method ...