Fluorine is a halogen gas located in Group 17 and has a wide number of uses due to its high reactivity. It is used in Toothpaste and antiseptics and widely used in the treatment of water to kill bacteria. Fluorine is the most reactive element in the periodic table due to its unique small nucleus and relatively low number of shells and electrons. It is highly corrosive and toxic to humans and has a very pungent odour. Fluorine was first used in 1530 by the German scientist Georgisu Agricola who used the mineral Fluorspar, more commonly known as Calcium Fluoride to extract metals from their ores. It was not until 1813 that the scientist Humphry Davy isolated Fluorine in the lab after collaborating with a number of scientists on Hydrofluoric acid. It is located in Group 17, the Halogens. It is a non metallic diatomic yellow gas at room temperature and it has a melting point of -219°c and a boiling point of -188°c.