Beyond the Periodic Table – Going for the Superheavy Elements
The first Periodic Table of the Elements was proposed by Dmitri Ivanovich Mendeleev in 1869, compiled on the basis of arranging the elements in ascending order of atomic weight and grouping them by similarity of chemical properties. He predicted the existence and properties of new elements and pointed out accepted atomic weights that were in error. At that time it was not known how far in the atomic weight we can go before elements become too unstable and radioactively decay. A century later it was assumed that the Periodic Table would end at nuclei with about 100 protons, because the attractive strong interactions could no longer counter-balance the Coulomb repulsion between the protons. In 1948, Goeppert-Mayer pointed out that nuclear shell closure effects will increase the nuclear stability substantially, and Meldner demonstrated in 1967 that the next proton/neutron shell closure (nuclear island of nuclear stability) will occur at the nuclear charge Z=114 and neutron number N=184, the next island of nuclear stability.
In the last decade we have seen the production of new elements for the Periodic Table up to nuclear charge 118. How far can we go? Where does the Period Table end? Can we do chemistry with such exotic elements? What is the chemical and physical behavior of these exotic elements?