Fluorine is a pale yellow gas with the chemical formula F₂, consisting of two fluorine atoms bonded together as the lightest member of the halogen family. As the most electronegative and reactive element on the periodic table, fluorine attacks nearly every substance it encounters, including glass, metals, and even water, which it sets on fire. First isolated in 1886 by French chemist Henri Moissan through electrolysis of hydrogen fluoride – a feat that earned him the Nobel Prize but also cost several earlier chemists their lives – fluorine’s extreme reactivity made it one of the last elements to be isolated despite being relatively common in Earth’s crust. Today, this “tiger of chemistry” is carefully harnessed for vital applications including uranium enrichment, pharmaceutical manufacturing, and producing fluoropolymers like Teflon, though its production and handling remain among the most dangerous operations in the chemical industry.

Find a review of the 50 most important industrial gases here.

20 Fun Facts About Fluorine

Beyond the basics above, what else should we know about Fluorine? Check out the 20 fun facts below!

1. Fluorine is so reactive it burns water, producing oxygen gas and hydrofluoric acid in a violently exothermic reaction at room temperature.
2. The gas etches glass by reacting with silicon dioxide, requiring storage in nickel, copper, or special steel containers pre-treated with fluorine.
3. Early fluorine chemists called it “the gas of Lucifer” after multiple deaths and injuries, including Moissan himself losing years of life.
4. Fluorine’s bond is surprisingly weak for such a reactive element – only 159 kJ/mol compared to chlorine‘s 243 kJ/mol.
5. The Manhattan Project consumed tons of fluorine to separate uranium isotopes using uranium hexafluoride gas diffusion.
6. Fluorine can oxidize oxygen itself, creating the rare compound oxygen difluoride (OF₂), one of the few oxygen compounds where oxygen has a positive oxidation state.
7. Teflon was discovered accidentally in 1938 when tetrafluoroethylene gas polymerized overnight in a cylinder, creating a mysterious white powder.
8. The element burns through brick, asbestos, and concrete, making laboratory accidents particularly catastrophic and difficult to contain.
9. Fluorine forms the strongest single bond in chemistry with hydrogen (567 kJ/mol), making hydrofluoric acid uniquely dangerous.
10. Rocket scientists tested fluorine as a propellant oxidizer but abandoned it after it proved too corrosive for any practical engine design.
11. Noble gases aren’t truly “noble” – fluorine forces even xenon and krypton to form compounds under the right conditions.
12. The gas has a sharp, pungent odor detectable at 0.1 ppm, but this concentration already causes eye and lung irritation.
13. Fluorine production requires more electricity per ton than aluminum smelting due to the extreme conditions needed for electrolysis.
14. ClF₃ (chlorine trifluoride) containing fluorine is so reactive it was investigated as a weapon that could burn through bunkers.
15. Tooth enamel contains fluorapatite, making it the hardest substance in the human body and resistant to acid decay.
16. The element exists in stars, created during helium burning, but is rare in the universe due to nuclear reaction pathways.
17. Industrial fluorine cells operate at 95°C using molten potassium bifluoride, consuming carbon anodes at 1 kg per ton of fluorine.
18. Fluorine reacts explosively with hydrogen even in complete darkness at -250°C, one of the few reactions occurring near absolute zero.
19. Modern processors use sulfur hexafluoride and nitrogen trifluoride for etching nanometer-scale features in silicon chips.
20. Despite fluorine’s reactivity, fluorocarbons are so stable they persist in the atmosphere for thousands of years, creating environmental concerns.

Thanks for reading!