Day 9: Interesting Facts About Fluorine
Atomic Symbol: F; Atomic Number: 9: Atomic Mass: 18.9984

1. Fluorine does not exist in nature as a free element, but it can be isolated through complex electrolysis and in 1906, the French chemist Ferdinand Frederic Henri Moissan won the Nobel Prize for being the first to do so.
2. Fluorine is the most chemically reactive element. It reacts, often very vigorously, with all of the other elements except oxygen, helium, neon and krypton.
3. Fluorine is most useful for its compounds such as uranium hexafluoride which is used for processing nuclear fuel, fluorocarbon in the production of teflon, sodium fluoride in toothpaste, hydrofluoric acid for etching glass (since HF can dissolve glass), and formerly Chlorofluorocarbons, which were used as refrigerants in air conditioning and freezers, until they were banned for causing ozone depletion.
4. The term fluorescence was coined as a response to how light emissions are induced in fluorite by radiating it with lesser wavelengths of ultraviolet light. Fluorescence microscopes widely used in drug tests and infectious disease diagnostics operate on the principles of fluorescence.

Image: Liquid fluorine at cryogenic temperatures.