Equilibrium of bromine. Image 2 of 4 in a series. Bromine is an element in which the liquid form easily vaporizes at room temperature. Bromine is a member of the halogen group of the periodic table, and is the only nonmetallic element that is a liquid at room temperature. Bromine derives its name from the Greek word for stench and is extremely toxic. The full series includes images 2r1515, 2r1516, 2r1519, and 2r1520.