Bromine is a chemical element, a reddish-brown liquid at room temperature that gives off toxic, choking fumes. It's one of only two elements that exist as liquids naturally (the other is mercury). The name comes from the Greek word for “stench” because of its harsh, unpleasant smell.

Chemists use the symbol Br to represent bromine on the periodic table. It belongs to a family of elements called halogens, which also includes chlorine, fluorine, and iodine. These elements are highly reactive, meaning they readily combine with other substances.

You encounter bromine compounds more often than you might think. Some swimming pools use bromine instead of chlorine to kill bacteria. Certain flame retardants in furniture and electronics contain bromine compounds that help prevent fires from spreading. Photographers once used silver bromide in film to capture images, though digital cameras have largely replaced this technology.

Bromine was discovered in 1826 by a French chemist named Antoine-Jérôme Balard, who found it in salt water from the Mediterranean Sea. Ocean water naturally contains small amounts of bromine. Because pure bromine is so dangerous and reactive, scientists handle it with extreme caution in laboratories, using special equipment and protective gear.