Measurements of the shell effect in atomic nuclei contribute
to finding out above which mass extremely heavy artificial elements no longer
decay.
The heaviest element on earth is uranium, which has the
atomic number 92 in the periodic table. Although superheavy elements up to
number 118 have been produced artificially, their atomic nuclei rapidly decay.
A subtle quantum effect means that even heavier atomic nuclei above element 120
could exist for years, however. Physicists have been searching for this
hypothetical “island of stability” for a long time.