Group 12 element Group 12 element Group 12, by modern IUPAC numbering, is a group of chemical elements in the periodic table. It includes zinc (Zn), cadmium (Cd) and mercury (Hg). The further inclusion of copernicium (Cn) in group 12 is supported by recent experiments on individual copernicium atoms. Formerly this group was named "IIB" (pronounced as "group two B", as the "II" is a Roman numeral) by CAS and old IUPAC system. The three group 12 elements that occur naturally are zinc, cadmium and mercury. They are all widely used in electric and electronic applications, as well as in various alloys. The
Extended periodic table be unbound and undergo proton emission. Cluster decay (heavy particle emission) has also been proposed as an alternative decay mode for some isotopes, posing yet another hurdle to identification of these elements. The following are the expected electron configurations of elements 118–173. Beyond element 122, no complete calculations are available and hence the data in this table must be taken as tentative. Extended periodic table An extended periodic table theorizes about chemical elements beyond those currently known and proven up through oganesson, which completes the seventh period (row) in the periodic table at atomic number ("Z") 118. If further elements