Meaning & use
fluorine
Last updated
Meaning
noununcountablechemistry
A pale yellow, poisonous gas that is the most reactive of all elements and is found in many minerals.
Grammar: Used without an or the when naming the substance: fluorine is a gas.
Patterns
- fluorine in something
- compounds of fluorine
Fluorine is so reactive that it attacks glass and most metals.
The chemistry teacher kept the sample of fluorine compounds sealed in a special container.
Fluorine has the symbol F on the periodic table.
Common combinations
- fluorine gas
- Fluorine gas must be handled with extreme care in a laboratory.
- a compound of fluorine
- Teflon is made from a compound of fluorine and carbon.
- contain fluorine
- Fluorite is a mineral that contains fluorine.
- fluorine atom
- Each fluorine atom needs just one more electron to fill its outer shell.
- traces of fluorine
- Traces of fluorine were found in the rock samples.
Synonyms and how they differ
- fluoride
- Fluoride names a compound or ion containing fluorine, such as the one in toothpaste, whereas fluorine is the pure element itself.
- halogen
- Halogen is the wider group of elements that includes fluorine, so it is a category rather than a name for this one element.
Word family
- fluoride noun
- a compound of fluorine, often added to drinking water
- fluoridate verb
- to add fluoride to something such as water
- fluorinate verb
- to treat a substance with fluorine
- fluorite noun
- a colorful mineral made of calcium and fluorine
Commonly confused: fluorine or fluoride? fluorine or chlorine?
fluorine vs fluoride
Fluoride is the compound that protects teeth; fluorine is the dangerous pure gas. Say 'fluoride toothpaste', never 'fluorine toothpaste'.
fluorine vs chlorine
Chlorine is a different element, a greenish gas used in swimming pools. It sits just below fluorine on the periodic table.
Practice
Which sentence uses the word correctly?
Choose one answer.
Fluorine is the reactive yellow gas. Toothpaste and water contain fluoride compounds, not the pure element, and fluorine is not a metal.
Make it your own
Write a sentence using “fluorine”, then check it and compare it with the examples above.