Bromine is a chemical element (atomic number 35) that, along with mercury, is one of a very few elements that are a liquid at normal temperatures and pressures. However, unlike mercury, it has a very low boiling point and will actually turn into a vapour at 58.8 C. In addition, like water, it will also evaporate at normal temperatures below its boiling point. In its liquid state, it is a brownish-red color. However, it is very reactive and readily combines with other elements to form compounds. As such, it is never found in its liquid state in nature. Although it is fairly rare, because its compounds are highly soluble in water, it is concentrated in the Earth's oceans.
Bromine does not appear to be required by living animals as a trace nutrient, but neither are its compounds very toxic.
Some bromine compounds have pharmaceutical uses, and some were used as pharmaceuticals in the past, but were replaced by other drugs. These compounds are used as anti-parasite medication. However, pure bromine is very toxic and can cause burns and breathing problems.