Extended periodic table table. The table below shows one possibility for the appearance of the eighth period, with placement of elements primarily based on their predicted chemistry. All of these hypothetical undiscovered elements are named by the International Union of Pure and Applied Chemistry (IUPAC) systematic element name standard which creates a generic name for use until the element has been discovered, confirmed, and an official name approved. These names are typically not used in the literature, and are referred to by their atomic numbers; hence, element 164 would usually not be called "unhexquadium" (the IUPAC systematic name), but rather "element 164" with
Extended periodic table 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 with higher atomic numbers than this are discovered, they will be placed in additional periods, laid out (as with the existing periods) to illustrate periodically recurring trends in the properties of the elements concerned. Any additional periods are expected to contain a larger number of elements than the seventh period, as they are calculated to have an additional so-called "g-block", containing at