Fluorine.

ETYM New Lat. fluorina: cf. German fluorin, French fluorine. So called from its occurrence in the mineral fluorite.
A nonmetallic univalent element; usually a yellow irritating toxic flammable gas; a powerful oxidizing agent; recovered from fluorite or cryolite or fluorapatite; SYN. F, atomic number 9.
Pale yellow, gaseous, nonmetallic element, symbol F, atomic number 9, atomic weight 19. It is the first member of the halogen group of elements, and is pungent, poisonous, and highly reactive, uniting directly with nearly all the elements. It occurs naturally as the minerals fluorite (CaF2) and cryolite (Na3AlF6). Hydrogen fluoride is used in etching glass, and the freons, which all contain fluorine, are widely used as refrigerants.
Fluorine was discovered by the Swedish chemist Karl Scheele in 1771 and isolated by the French chemist Henri Moissan in 1886.
Combined with uranium as UF6, it is used in the separation of uranium isotopes. + prikaži više