"Br-" is the chemical symbol for the element bromine, which is a reddish-brown liquid at room temperature. It belongs to the group of elements known as halogens, which also includes fluorine, chlorine, iodine, and astatine. Bromine is known for its strong odor and is commonly used in flame retardants, pesticides, and certain types of pharmaceuticals. Bromine is unique among the halogens as it is the only one that is a liquid at standard conditions. It has a relatively low boiling point compared to other halogens and can easily evaporate into a gas. Due to its reactivity, bromine is often found in nature in the form of compounds rather than in its elemental state.