It becomes yellow after some time due to self-damage by the alpha radiation given off by radium when it decays.
Small amounts of barium impurities give the compound a rose color.
Like radium chloride, crystallization from aqueous solution gives the dihydrate RaBr2·2H2O, isomorphous with its barium analog.
The ionizing radiation emitted by radium bromide excites nitrogen molecules in the air, making it glow.
[6] The large ionic radius of Ra2+ (148 pm) results in weak complexation and poor extraction of radium from aqueous solutions when not at high pH.