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
Alternative periodic tables expanded, but not changed as a principle. The oldest periodic table is the short form table (columns I–VIII) by Dmitri Mendeleev, which shows secondary chemical kinships. For example, the alkali metals and the coinage metals (copper, silver, gold) are in the same column because both groups tend to have a valence of one. This format is still used by many, as shown by this contemporary Russian short form table, which includes all elements and element names until roentgenium. H. G. Deming used the so-called long periodic table (18 columns) in his textbook "General Chemistry", which appeared in the USA for