Bromine Bromine Bromine is a chemical element with symbol Br and atomic number 35. It is the third-lightest halogen, and is a fuming red-brown liquid at room temperature that evaporates readily to form a similarly coloured gas. Its properties are thus intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig (in 1825) and Antoine Jérôme Balard (in 1826), its name was derived from the Ancient Greek βρῶμος ("stench"), referencing its sharp and disagreeable smell. Elemental bromine is very reactive and thus does not occur free in nature, but in colourless soluble crystalline mineral halide salts,
Fluorine perchlorate and perchlorates, it needs to be handled with extreme caution. FClO is a strong oxidant and it reacts with iodide ion: FClO can also react with tetrafluoroethylene: It may be a radical addition reaction. Fluorine perchlorate Perchloryl Hypofluorite is the rarely encountered chemical compound of fluorine, chlorine, and oxygen with the chemical formula or . It is an extremely unstable gas that explodes spontaneously and has a penetrating odor. One synthesis uses fluorine and perchloric acid, though the action of ClF on water is another method. Another method of synthesis involves the thermal decomposition of tetrafluoroammonium perchlorate, , which yields