Radium sulfite would have the molecular formula
of RaSO3 and the molecular weight of 306.0866
g/mol. It could be prepared by the reaction of RaO
and gaseous SO2 at an elevated temperature of about
650°C:
RaO(solid)+ SO2(gas)→RaSO3(solid)
However, there is no report of this salt ever having
been prepared.
There is no demand for this salt and it is not clear
whether it has ever existed. It is not available
commercially.