High Quality Content by WIKIPEDIA articles! The boron group is the series of elements in group 13 (IUPAC style) of the periodic table, comprising boron (B), aluminium (Al), gallium (Ga), indium (In), thallium (Tl), and ununtrium (Uut). The elements in the boron group are characterized by having three electrons in their outer energy levels (valence layers). These elements have also been referred to as earth metals and as triels.