Thorium thiosulphates

Sodium thiosulphate solution precipitate of thorium hydroxide and sulphur on boiling (distinction from cerium). 

Sodium thiosulphate solution no precipitate (distinction from thorium and from cerium(IV) ions). 

Thorium is sometimes regarded as a rare earth element but it is wise to restrict the term to yttrium and the elements lying between aijd including lanthanum and lutecium — for these are trivalent aq,d closely similar, whereas thorium is tetravalent and presents many other contrasts. In many ways it resembles scandium, which we have ajready seen to differ in several important ways from the rare earth metals. Thus, like scandium, thorium yields an insoluble fluoride, an acetyl-acetonate that sublimes without decomposition and a basic -thiosulphate. The rare earth metals do none of these things. 

No experimental information is available on aqueous thiosulphate complexes of thorium. 

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