Seaborgium, which was as recently as 1994 known by the name, "Element 106," was discovered in June of 1974 by two independent groups of scientists attempting to synthesize the element in a laboratory setting.
Seaborgium is known as a "transuranium" element, which means it is higher than uranium, atomic number 93, on the periodic table. Uranium is the heaviest element to have been discovered in nature; therefore, transuranium elements are only available by laboratory synthesis. Transuranium elements are also highly unstable, and the radioactivity of seaborgium is demonstrated in its half-life of less than a second. Because it is so highly unstable, it cannot be photographed nor collected, so little is known about the physical properties of the element. Only a few atoms at a time can be synthesized. The atomic number of seaborgium is 106, and the mass number for the longest living isotope of the element is 266.
At the time of its discovery in 1974, an element with 106 protons in its nucleus had neither been found in nature nor synthesized in a lab, and both labs were deliberately attempting to create the element in order to gain credit for its discovery. According to the CRC Handbook of Chemistry and Physics, the two groups credited for the successful creation of Seaborgium were members of the Joint Institute for Nuclear Research in Dubna, Soviet Union, and employees of the Lawrence Berkeley and Livermore Laboratories in the United States. Ultimately, the international scientific community credited the United States laboratory with the discovery of the element.
The Lawrence Berkeley Laboratory (http://www.lbl.gov) reports that the synthesis at the Berkeley Lab involved using a particle accelerator known as the Heavy Ion Linear Accelerator (HILAC) to bombard isotopes of californium (Cf) with boron beams, which originally resulted in the production of lawrencium in 1961. The particles were isolated from the californium and boron with a particle separator. Further experimentation, including changing the combinations of isotopes used in the particle accelerator, resulted in the discovery of Elements 104-112. The 249-isotope of californium and a series of alpha decays produced Element 106, Sg, Seaborgium.
When Seaborgium was finally named in 1994, it was named after Nobel Prize winner and former Manhattan Project scientist Glenn Theodore Seaborg of the Lawrence Berkeley Laboratory. As a result of an international dispute between the two credited groups, the International Union of Pure and Applied Chemistry (IUPAC) revoked the name the same year for reconsideration. After much debate, the name "seaborgium" was officially reinstated in 1997. According to a tribute article posted at the Lawrence Berkeley Laboratory (http://www.lbl.gov), Dr. Seaborg was the first living person to have an element named after him.