  The heaviest of the transuranic elements known as superheavy elements (SHE)
are produced in nuclear reactions in a few specialized laboratories located in
Germany, the U.S., Russia, and Japan. The history of this branch of physical
science provides several case studies of interest to the philosophy and
sociology of modern science. The story of SHE illuminates the crucial notion of
what constitutes a chemical element, what the criteria are for discovering a
new element, and how an element is assigned a name. The story also cast light
on the sometimes uneasy relationship between physics and chemistry. It is far
from obvious that elements with Z > 110 exist in the same sense as oxygen or
sodium exists. The answers are not given by nature but by international
commissions responsible for the criteria and evaluation of discovery claims.
The works of these commissions and of SHE research in general have often been
controversial.
