РАДИУСУЛЬФАТ

Radium sulfate has the molecular formula of RaSO4 and the molecular weight of 322.0626 g/mol. It can be prepared by dissolving radium oxide in sodium sulfate solution:
RaO+Na2SO4+H2O ? RaSO4+NaOH
Radium sulfate is insoluble in water with a solubility product of 3.66×10^-11. The solubility of radium sulfate would appear as at least 100-fold less than barium sulfate. Thus, it is the most insoluble sulfate known. Its CAS Number is 7446-16-4. It appears as white crystals. Since radium is a decay product in the ²³⁸U series which then allows radon to accumulate in household basements, it is RaSO₄ that has received some attention in the scientific literature.

white, rhomb crystal(s) when pure, else colored yellow, orange, pink; radioactive [HAW93] [CRC10]

Radium sulfate (RaSO4) is the most insoluble sulfate known in chemistry and is created when radium combines with a sulfate ion (Ra + H2SO4 → RaSO4 + H2↑).