For many years Chlorofluorocarbons (CFCs) were used for freezers and air conditioners.Today they have been banned because they damage the ozone layer.Fluoride research had its beginnings in 1901, when a young dental school graduate named Frederick Mc Kay left the East Coast to open a dental practice in Colorado Springs, Colorado.When he arrived, Mc Kay was astounded to find scores of Colorado Springs natives with grotesque brown stains on their teeth.However, the assumption of contemporaneity may not always be correct.This is due to the fact that one or both of the objects may have been moved or redeposited into a different location.It is readily found in minerals in the Earth's crust including fluorspar, fluorapatite, and cryolite.
The nearly anhydrous acid was prepared in 1809, and two years later the French physicist , “to flow.” The mineral subsequently proved to be a source of the element, which was accordingly named fluorine.Fluorine is the first element in the group of halogens which occupies the 17th column of the periodic table. It is a fairly rare element in the universe, but is the thirteenth most common element in the Earth's crust. It is also the most electronegative of the elements, meaning that it attracts electrons towards itself.Characteristics and Properties Fluorine's most notable characteristic is that it is the most reactive of all the elements. In standard conditions fluorine forms a gas made up of two fluorine atoms called a diatomic gas.For instance, if we find a fossil bone below the strata 3 rock level shown above, we assume that the animal most likely lived at a time before that layer was formed.However, we must be careful to note whether or not the fossil comes from the mixed strata zone of the filled in hole..