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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]
Fluoride is classified as a weak base since it only partially associates in solution, but concentrated fluoride is corrosive and can attack the skin. Fluoride is the simplest fluorine anion. In terms of charge and size, the fluoride ion resembles the hydroxide ion.
Fluorine is the 13th most abundant element in Earth's crust at 600–700 ppm (parts per million) by mass. [61] Though believed not to occur naturally, elemental fluorine has been shown to be present as an occlusion in antozonite, a variant of fluorite. [62] Most fluorine exists as fluoride-containing minerals.
Ingested fluoride forms hydrofluoric acid in the stomach. In this form, fluoride crosses cell membranes and then binds with calcium and interferes with various enzymes. Fluoride is excreted through urine. Fluoride exposure limits are based on urine testing, which is used to determine the human body's capacity for ridding itself of fluoride. [69 ...
That decision does not necessarily mean fluoride must be removed from U.S. drinking water—the EPA can choose to address the situation in a number of ways, including releasing a public notice ...
As indicated throughout this article, fluorine-substituents lead to reactivity that differs strongly from classical organic chemistry. The premier example is difluorocarbene, CF 2, which is a singlet whereas carbene (CH 2) has a triplet ground state. [12] This difference is significant because difluorocarbene is a precursor to tetrafluoroethylene.
The science behind fluoride The fluoride issue goes well beyond medical freedom. The latest tactic used by anti-fluoride activists mirrors that of anti-vaccine groups: strike fear in the hearts of ...
A U.S. government report expected to stir debate concluded that fluoride in drinking water at twice the recommended limit is linked with lower IQ in children. The report, based on an analysis of ...