Dubnium

In 1968, lead researcher Georgy Flerov (sometimes spelled Georgii Flyorov) reported that his team at Russia’s Joint Institute for Nuclear Research (JINR) created a few atoms of element 105. They did so by bombarding amercium-243 with neon-22. The two nuclei combined, or fused, and a few neutrons popped out. The evidence that they created a new element was based on the analysis of emerging alpha particles (two protons and two neutrons, a helium nuclei), a common radioactive emission.

In 1970, an American team at the Lawrence Berkeley Laboratory in California, led by Albert Ghiorso, bombarded californium-249 with nitrogen-15. Interestingly, their alpha-particle data conflicted with the JINR team's. The American team demonstrated that they produced an isotope of element 105 with a mass of 260. Their data indicated that JINR had not actually produced isotopes of mass 260. However, the JINR team had continued their research and published new results giving further evidence that they had produced isotopes of element 105 with a mass of 261, and possibly 260.

In 1997, the International Union of Pure and Applied Chemistry (IUPAC) decided that the credit for discovery should be shared, but the element should be named dubnium after Dubna, Russia, where JINR is located.

Research into the chemical properties of dubnium are limited. Given its short half-life, it is exceedingly difficult to work with this element and impossible to measure its properties. Even its atomic mass is unknown—there isn't enough of the element to weigh. It is simply listed as the mass number of its longest-lived isotope, 268.

With just a handful of atoms ever created, studies on dubnium have only been conducted on individual atoms. Still, the results generally align with theoretical predictions. Dubnium should behave like vanadium, niobium, and tantalum, which are directly above it on the periodic table.

Dubnium has no known uses beyond fundamental research.

Like all synthetic, high-atomic-number elements, dubnium is extremely radioactive and has no stable isotopes. Of its 13 known isotopes, its longest-lived, dubnium-268, has a half-life of only 16 hours. Most of the others last only seconds or fractions of a second.

Dubnium is a purely synthetic element and does not occur in nature.