the experimental procedures of transactinide synthesis. This list was finally accepted by the American Chemical Society, which wrote: Seaborg commented regarding the naming: Seaborg died a year and a half later, on 25 February 1999, at the age of 86. Isotopes Superheavy elements such as seaborgium are produced by bombarding lighter elements in particle accelerators that induces fusion reactions. Whereas most of the isotopes of seaborgium can be synthesized directly this way, some heavier ones have only been observed as decay products of elements with higher atomic numbers. Depending on the energies involved, fusion reactions that generate superheavy elements are separated into "hot" and "cold". In hot fusion reactions, very light, high-energy projectiles are accelerated toward very heavy targets (actinides), giving rise to compound nuclei at high excitation energy (~40–50 MeV) that may either fission or evaporate several (3 to 5) neutrons. In cold fusion reactions, the produced fused nuclei have a relatively low excitation energy (~10–20 MeV), which decreases the probability that these products will undergo fission reactions. As the fused nuclei cool to the ground state, they require emission of only one or two neutrons, and thus, allows for the generation of more neutron-rich products. The latter is a distinct concept from that of where nuclear fusion claimed to be achieved at room temperature conditions (see cold fusion). Seaborgium has no stable or naturally occurring isotopes. Several radioactive isotopes have been synthesized in the laboratory, either by fusing two atoms or by observing the decay of heavier elements. Thirteen different isotopes of seaborgium have been reported with mass numbers 258–269 and 271, three of which, seaborgium-261, 263, and 265, have known metastable states. All of these decay only through alpha decay and spontaneous fission, with the single exception of seaborgium-261 that can also undergo electron capture to dubnium-261. There is a trend toward increasing half-lives for the heavier isotopes, though even–odd isotopes are generally more stable than their neighboring even–even isotopes, because the odd neutron leads to increased hindrance of spontaneous fission; among known seaborgium isotopes, alpha decay is the predominant decay mode in even–odd nuclei whereas fission dominates in even–even nuclei. Three of the heaviest known isotopes, 267Sg, 269Sg, and 271Sg, are also the longest-lived, having half-lives on the order of 1 minute. Some other isotopes in this region are predicted to have comparable or even longer half-lives. Additionally, 263Sg, 265Sg, 265mSg, and 268Sg have half-lives measured