Fluorine

[floo r-een, -in, flawr-, flohr-] /ˈflʊər in, -ɪn, ˈflɔr-, ˈfloʊr-/

noun, Chemistry.
1.
the most reactive nonmetallic element, a pale-yellow, corrosive, toxic gas that occurs combined, especially in fluorite, cryolite, phosphate rock, and other minerals. Symbol: F; atomic weight: 18.9984; atomic number: 9.
/ˈflʊəriːn/
noun
1.
a toxic pungent pale yellow gas of the halogen group that is the most electronegative and reactive of all the elements, occurring principally in fluorspar and cryolite: used in the production of uranium, fluorocarbons, and other chemicals. Symbol: F; atomic no: 9; atomic wt: 18.9984032; valency: 1; density: 1.696 kg/m³; relative density: 1.108; freezing pt: –219.62°C; boiling pt: –188.13°C
n.

non-metallic element, 1813, coined by English chemist Sir Humphry Davy (1778-1829) from fluorspar (“calcium fluoride,” modern fluorite), the late 18c. name of the mineral where it was first found; see fluor + chemical suffix -ine (2). Not isolated until 1886.

fluorine fluor·ine (flur’ēn’, -ĭn, flôr’-)
n.
Symbol F
A highly corrosive poisonous gaseous halogen element, the most reactive of all the elements. Atomic number 9; atomic weight 18.9984; melting point -219.62°C; boiling point -188.14°C (at 1 atmosphere); specific gravity of liquid 1.108 (at boiling point); valence 1.
fluorine
(flr’ēn’)
Symbol F
A pale-yellow, poisonous, gaseous element of the halogen group. It is highly corrosive and is used to separate certain isotopes of uranium and to make refrigerants and high-temperature plastics. It is also added in fluoride form to the water supply to prevent tooth decay. Atomic number 9; atomic weight 18.9984; melting point -223°C; boiling point -188.14°C; specific gravity of liquid 1.108 (at boiling point); valence 1. See Periodic Table.