The periodic table exists because, long before chemists were aware of electrons, they noticed patterns in the chemistry of elements and placed them in the same columns. Consequently, one can usually ...
Superheavy elements are those elements with a large number of protons in their nucleus. Elements with more than 92 protons are unstable; they decay to lighter nuclei with a characteristic half-life.
1951: Edwin Mattison McMillan and Glenn Theodore Seaborg, "for their discoveries in the chemistry of the transuranium elements." 1950: Otto Paul Hermann Diels and Kurt Alder, "for their discovery ...