What element has the symbol 'F'?

The story behind the answer

Fluorine is the element with the symbol F. It’s element 9, a halogen in group 17. Remember: “F is for Fluorine,” while Fe is iron, Au is gold, and Fr is francium—handy for avoiding symbol mix-ups.

Fluorine is a pale yellow-green gas at room temperature, the most electronegative element and among the most reactive nonmetals. In compounds it often appears as the fluoride ion (F−), which is not the same as elemental fluorine; fluoride is what’s used in toothpaste and water fluoridation. The name comes from the mineral fluorite, and fluorine chemistry enables materials like Teflon and processes like uranium enrichment (as UF6).