Extended periodic table The next six elements on the periodic table should be the last main-group elements in their period. In elements 167 to 172, the 9p and 8p shells will be filled. Their energy eigenvalues are so close together that they behave as one combined "p" shell, similar to the non-relativistic 2p and 3p shells. Thus, the inert pair effect does not occur and the most common oxidation states of elements 167 to 170 should be +3, +4, +5, and +6 respectively. Element 171 (unseptunium) is expected to show some similarities to the halogens, showing various oxidation states ranging from −1 to
Group (periodic table) names to mean different things. The new system simply numbers the groups increasingly from left to right on the standard periodic table. The IUPAC proposal was first circulated in 1985 for public comments, and was later included as part of the 1990 edition of the "Nomenclature of Inorganic Chemistry". Group (periodic table) In chemistry, a group (also known as a family) is a column of elements in the periodic table of the chemical elements. There are 18 numbered groups in the periodic table, and the f-block columns (between groups 3 and 4) are not numbered. The elements in a group