Bromine (Br) has two stable isotopes, 79Br and 81Br, and 30 known radioisotopes, the most stable of which is 77Br, with a half-life of 57.036 hours. Bromine and chlorine are the only halogens with more than one stable isotope.
Relative atomic mass: 79.904(1)
Notes
References
Isotopes of bromine Wikipedia(Text) CC BY-SA