Bromine is a chemical element with the symbol Br. It is a reddish-brown liquid that is volatile and highly reactive. It belongs to the halogen group and is found naturally in the Earth's crust and in seawater. Bromine is used in various industries, including pharmaceuticals, agriculture, and water treatment. It has several applications, such as flame retardants, disinfectants, and dyes. In the periodic table, bromine is located in group 17 and period 4. Its atomic number is 35, and its atomic weight is 79.904.