Group III consists of two subgroups: group IIIb and group IIIa. Group IIIa consists of scandium, yttrium, and lanthanium, which is generally considered with the lanthanoids, and actinium, which is classified with the actinoids. Group IIIb, the main group, comprises boron, aluminium, gallium, indium, and thallium.
Scope note is not available.