ABSTRACT
Geochemical and biochemical properties, as well as the abundance in the biosphere, of all the trace and rare elements of Group III (new group 13) are highly divergent. The geochemistry of Group IIIa elements is especially complicated, reflecting a wide range in occurrence and behavior from B, the lightest nonmetal, to amphoteric Al, which is one of the basic constituents of the lithosphere. Ga, In, and Tl (the latter two being widely distributed elements in the lithosphere and biosphere) also belong to this group. A strong affinity for oxygen and the predominant
3 state are common characteristics of these elements. In Group IIIb (new group 3) Sc and Y are very rare in the environment. Other rare elements are subdivided into the lanthanides and actinides, of which many are natural or artificial radionuclides.
