Bromine is a highly reactive element that can form bonds with many different elements, including magnesium, silver, oxygen, chlorine and zinc. Most bromine found in the world is in the form of salts, such as potassium bromide and sodium bromide.
Bromine reacts violently when combined with any of the alkali metals, such as lithium, sodium, potassium, rubidium or cesium. Violent reactions also occur when it is combined with aluminum, arsenic, antimony or phosphorous.
Together with mercury, bromine is one of only two elements to exist as a liquid in its natural state, although it is so highly reactive that pure bromine does not exist in nature.