- Seaborgium (Sg) is a synthetic, radioactive element with atomic number 106, belonging to Group 6 of the periodic table, directly below tungsten and molybdenum.
- It is a transactinide element, part of the 6d transition series. Its electron configuration is predicted as [Rn] 5f¹⁴ 6d⁴ 7s², consistent with its position in Group 6, though relativistic effects may influence its actual orbital arrangement.
- Seaborgium is expected to display a predominant oxidation state of +6, like tungsten, with additional lower states such as +5 and +4 possible under reducing conditions. Its atomic structure consists of one hundred and six protons, usually one hundred and sixty-nine neutrons in seaborgium-275 (²⁷⁵Sg), and one hundred and six electrons distributed across seven shells.
- The most stable isotope identified so far is seaborgium-271 (²⁷¹Sg), with a half-life of about 2 minutes, while others range from milliseconds to a few seconds.
- Seaborgium was first synthesized in 1974 by a team at Lawrence Berkeley National Laboratory and Lawrence Livermore National Laboratory in California, led by Albert Ghiorso. The team bombarded californium-249 (²⁴⁹Cf) with oxygen-18 ions in a heavy-ion accelerator, producing atoms of seaborgium-263 (²⁶³Sg). Almost simultaneously, a group at the Joint Institute for Nuclear Research (JINR) in Dubna, Soviet Union, claimed to have produced element 106 in 1974 by bombarding lead-208 (²⁰⁸Pb) with chromium-54 ions. The competing claims fueled another chapter in the Cold War naming disputes over superheavy elements.
- The American team proposed the name seaborgium in honor of Glenn T. Seaborg, the Nobel Prize–winning chemist who was instrumental in the discovery of many actinides, including plutonium, americium, curium, berkelium, and californium. This was controversial because Seaborg was still alive at the time, breaking with the convention that elements should not be named after living persons. After lengthy debate, the International Union of Pure and Applied Chemistry (IUPAC) officially approved the name seaborgium in 1997, making Seaborg the first person to have an element named after him during his lifetime.
- Due to its extremely short half-life and the fact that it can only be synthesized atom by atom, seaborgium has no practical or commercial applications. Its value lies solely in advancing scientific understanding of the chemical properties of superheavy elements and testing theoretical predictions of quantum mechanics in the transactinide region.
- Chemically, seaborgium exhibits properties consistent with its placement in Group 6. Studies on single atoms indicate it forms volatile compounds such as seaborgium hexacarbonyl (Sg(CO)₆), similar to the hexacarbonyls of molybdenum and tungsten. It also forms halides such as seaborgium(VI) chloride (SgCl₆). These findings confirm that seaborgium behaves much like its lighter congeners, though relativistic effects slightly modify its chemical characteristics.
- Biologically, seaborgium has no natural role and is considered highly radiotoxic. Because it can only be produced in vanishingly small amounts, it poses no biological or environmental risk outside of controlled laboratory experiments.
- Environmentally, seaborgium does not occur in nature. It is produced only in nuclear research facilities, decays within minutes or less, and leaves no lasting environmental presence.
