The boron group is the series of elements in group 13 (IUPAC style) in the periodic table. The boron group consists of boron (B), aluminium (Al), gallium (Ga), indium (In), thallium (Tl), and ununtrium (Uut). The group has previously also been referred to as the earth metals and the triels, from the Latin tri, three, stemming from the naming convention of this group as Group IIIB. These elements are characterized by having three electrons in their outer energy levels (valence layers). Boron is considered a metalloid, and the rest are considered metals of the poor metals groups. Boron occurs sparsely probably because of disruption of its nucleus by bombardment with subatomic particles produced from natural radioactivity. Aluminium occurs widely on earth and in fact, it is the third most abundant element in the Earth's crust (7.4%).
