Radium bromide the air causes this luminescence. Radium bromide is also very dangerous since the crystals occasionally explode. Helium gas evolved from alpha particles can accumulate within the crystals which cause them to weaken and rupture. Another property of radium bromide is its ability to crystallize from an aqueous solution. It forms a dihydrate, very similar to barium bromide. The chemical radium bromide is not found in nature; it is created. To extract radium from uranium or pitchblende ores, the most common practice is called the Curie method which it involves two major stages. The first stage is a chemical treatment to
Radium lower-energy than the beta radiation emitted by promethium) which cannot penetrate the skin, rather than the penetrating gamma radiation of radium and is regarded as safer. Clocks, watches, and instruments dating from the first half of the 20th century, often in military applications, may have been painted with radioactive luminous paint. They are usually no longer luminous; however, this is not due to radioactive decay of the radium (which has a half-life of 1600 years) but to the fluorescence of the zinc sulfide fluorescent medium being worn out by the radiation from the radium. The appearance of an often thick