Antoine Jérôme Balard in the context of Balard (Paris Métro)

Bromine is a chemical element; it has symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are 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 Ancient Greek βρῶμος (bromos) 'stench', referring to its sharp and pungent smell.

Elemental bromine is very reactive and thus does not occur as a free element in nature. Instead, it can be isolated from colourless soluble crystalline mineral halide salts analogous to table salt, a property it shares with the other halogens. While it is rather rare in the Earth's crust, the high solubility of the bromide ion (Br) has caused its accumulation in the oceans. Commercially the element is easily extracted from brine evaporation ponds, mostly in the United States and Israel. The mass of bromine in the oceans is about one three-hundredth that of chlorine.

Carl Jacob Löwig (17 March 1803 – 27 March 1890) was a German chemist and discovered bromine independently of Antoine Jérôme Balard.

He received his PhD at the University of Heidelberg for his work with Leopold Gmelin. During his research on mineral salts he discovered bromine in 1825, as a brown gas evolving after the salt was treated with chlorine.