FLUORINE

fluorine, atomic number

(noun) a nonmetallic univalent element belonging to the halogens; usually a yellow irritating toxic flammable gas; a powerful oxidizing agent; recovered from fluorite or cryolite or fluorapatite

Source: WordNet® 3.1

Etymology

Noun

fluorine (countable and uncountable, plural fluorines)

(uncountable) The chemical element (symbol F) with an atomic number of 9. It is the lightest of the halogens, a pale yellow-green, highly reactive gas that attacks all metals.

Hypernym: halogen

(chemistry, countable) A single atom of this element.

Source: Wiktionary

Flu"or*ine ( or ; 104), n. Etym: [NL. fluorina: cf. G. fluorin, F. fluorine. So called from its occurrence in the mineral fluorite.] (Chem.)

Definition: A non-metallic, gaseous element, strongly acid or negative, or associated with chlorine, bromine, and iodine, in the halogen group of which it is the first member. It always occurs combined, is very active chemically, and possesses such an avidity for most elements, and silicon especially, that it can neither be prepared nor kept in glass vessels. If set free it immediately attacks the containing material, so that it was not isolated until 1886. It is a pungent, corrosive, colorless gas. Symbol F. Atomic weight 19.

Note: Fluorine unites with hydrogen to form hydrofluoric acid, which is the agent employed in etching glass. It occurs naturally, principally combined as calcium fluoride in fluorite, and as a double fluoride of aluminium and sodium in cryolite.

Source: Webster’s Unabridged Dictionary 1913 Edition