Radium chloride radium chloride is weakly paramagnetic with a magnetic susceptibility of 1.05. It also differs from barium chloride by the flame color, which is red as opposed to green for barium chloride. Radium chloride is still used for the initial stages of the separation of radium from barium during the extraction of radium from pitchblende. The large quantities of material involved (tonnes of ore for milligrams of radium) favour this less costly (but less efficient) method over those based on radium bromide or radium chromate (used for the later stages of the separation). It was also used in medicine to produce
Radium-223 Radium-223 Radium-223 (Ra-223, Ra) is an isotope of radium with an 11.4-day half-life, in contrast to the more common isotope radium-226, discovered by the Curies, which has a 1601-year half-life. The principal use of radium-223, as a radiopharmaceutical to treat metastatic cancers in bone, takes advantage of its chemical similarity to calcium, and the short range of the alpha radiation it emits. Although radium-223 is formed naturally in trace amounts by the decay of uranium-235, it is generally made artificially, by exposing natural radium-226 to neutrons to produce radium-227, which decays with a 42-minute half-life to actinium-227. Actinium-227 (half-life 21.8