ABSTRACT

Geochemical and biochemical properties of the elements of Group 3, as well as their abundance in the biosphere are highly divergent. Two elements, scandium (Sc) and yttrium (Y) are rather rare in the environment, and usually exhibit the af nity for oxygen and their oxidation state is mainly +3 (Table 8.1). Two other elements, lanthanum (La) and actinum (Ac) are associated with two subgroups of elements: lanthanides and actinides, of which many elements are either natural or arti cial radionuclides.