Bromine (Br) is a chemical element with atomic number 35. It belongs to a group of elements called halogens, and like other halogens, bromine is highly reactive.

There are two stable bromine isotopes, ⁷⁹Br and ⁸¹Br, and they're almost equally abundant, giving bromine an atomic weight near 80.

Bromides (i.e. negative ions of bromine, Br⁻) were frequently used as sedatives in the past, but have since been replaced by safer and more effective drugs.