On the periodic table, bromine is the only element liquid at room temperature besides mercury.
Bromine is a halogen in group 17 and period 4. At ordinary room temperatures it is a dense, volatile, reddish-brown liquid that gives off an irritating vapor. Its name comes from the Greek word bromos, meaning “stench,” reflecting its strong odor.
Bromine was independently identified in the early nineteenth century. Antoine Jérôme Balard discovered it in 1826 from brine residues near Montpellier, France, and Justus von Liebig had examined the substance earlier. Bromine is usually found in nature as bromide salts rather than as free elemental bromine.
The melting point of bromine is about −7.2 °C, while its boiling point is about 58.8 °C. Gallium, cesium, and rubidium can melt near or slightly above room temperature, but they are solids at typical room conditions.