Voyage to SUPERHEAVY Island; January 2000; Scientific American Magazine; by Oganessian, Utyonkov, Moody; 5 Page(s)

The creation of the element neptunium in the spring of 1940 launched chemists on a fascinating journey into uncharted terrain. In this transuranic world, atoms whose nuclei have more than the 92 protons of a uranium nucleus exhibit unusual or unique properties. With their large numbers of electrons, these heavy elements have given chemists invaluable insights into the arrangement of electrons in atoms and into chemical bonding. The elements have also found uses in technologies ranging from nuclear weapons to smoke detectors.

So far this research has produced 23 new elements with atomic nuclei that have more protons than uranium atoms do. Of those 23, only the "lightest" two-neptunium and plutonium-exist at all in nature.