fluorine

[ floor-een, -in, flawr-, flohr- ]

/ ˈflʊər in, -ɪn, ˈflɔr-, ˈfloʊr- /

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noun Chemistry.

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.

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Origin of fluorine

First recorded in 1805–15; fluor(ic) + -ine¹

Words nearby fluorine

fluoridation, fluoride, fluoridize, fluorimeter, fluorinate, fluorine, fluorine dating, fluorite, fluoro-, fluorocarbon, fluorochemical

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use fluorine in a sentence

Fifty-two percent of those products contained a high fluorine level, suggesting it contained at least one PFAS.
Lots of makeup may contain potentially harmful ‘forever chemicals’|Maria Temming|August 13, 2021|Science News For Students
Adding fluorine to fentanyl showed increased opioid activity in the more acidic conditions of injured tissue compared to healthy tissue.
Chemists think they’ve found a way to make opioids less addicting|Purbita Saha|July 17, 2021|Popular-Science
Over the last three years, researchers tested 231 cosmetics products in North America for fluorine, an indicator of per- and polyfluoroalkyl substances, or PFAS.
Senate bill would ban toxic ‘forever chemicals’ in makeup, which new study found are often unlabeled|Tik Root|June 15, 2021|Washington Post
Among over 200 tested beauty products, about half contained high levels of fluorine — a marker for potentially harmful PFAS compounds.
Many cosmetics contain hidden, potentially dangerous ‘forever chemicals’|Maria Temming|June 15, 2021|Science News

Long-lasting or waterproof products were especially likely to contain lots of fluorine.
Many cosmetics contain hidden, potentially dangerous ‘forever chemicals’|Maria Temming|June 15, 2021|Science News
Calcium also occurs, combined with fluorine, in the mineral fluor (CaF2).
A Textbook of Assaying: For the Use of Those Connected with Mines.|Cornelius Beringer and John Jacob Beringer
Fluorine is frequently met with as calcium fluoride or fluor-spar (CaF2).
A Textbook of Assaying: For the Use of Those Connected with Mines.|Cornelius Beringer and John Jacob Beringer
If the substance contained fluorine, the characters will be found permanently etched on the glass.
A Textbook of Assaying: For the Use of Those Connected with Mines.|Cornelius Beringer and John Jacob Beringer
The increase in weight multiplied by 0.655 gives the weight of fluorine.
A Textbook of Assaying: For the Use of Those Connected with Mines.|Cornelius Beringer and John Jacob Beringer
The loss in weight gives that of the silicon fluoride (SiF4), which, multiplied by 0.7307, gives the weight of fluorine.
A Textbook of Assaying: For the Use of Those Connected with Mines.|Cornelius Beringer and John Jacob Beringer

British Dictionary definitions for fluorine

fluorine

fluorin (ˈflʊərɪn)

/ (ˈflʊəriːn) /

noun

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

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for fluorine

fluorine

[ flur′ēn′ ]

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.