Fluorine

Fluorine 18.9984032(5)   F 9 1s22s22p5 [ ? ] Halogen: Properties: Yellow, corrosive, toxic gas. Very pungent odor. Highly reactive and electronegative. Uses: Pharmaceuticals, pesticides, plastics (Teflon). Hazard: Highly toxic. Dangerously powerful oxidant.

Fluorine is a chemical element, typically found as a gas in its elemental form. It has the chemical symbol F, atomic number (number of protons) Z = 9, and a standard atomic weight of 18.9984032 g/mol.

Fluorine is considered to be a member of the "Halogen" class of elements. At a pressure of 101.325 kPa, it has a boiling point of −182.12 °C, and a melting point of −219.67 °C