Bromine

Bromine is a naturally occurring element that is often found in the earth's crust and in seawater in various forms. It's a dark, reddish-brown liquid at room temperature and is the only non-metallic element that is liquid. Bromine is used in many areas such as agricultural chemicals, dyestuffs, insecticides, and pharmaceuticals. It's also used in fire retardants because it reduces the flammability of objects. In the human body, bromine is not considered essential for humans as it's often found in trace amounts and its role is not very well understood. However, it's known to interact with certain tissues in the body and can influence the central nervous system. It's important to note that while bromine is used in various industries, excessive exposure can be harmful. Therefore, it's always handled with care in an industrial setting.