Dubnium is a metallic chemical element in the transactinide series on the periodic table of elements. Like other elements in this group, it is radioactive and its isotopes have extremely short half lives, making it very difficult to study. As a result, no commercial uses for dubnium have been developed; the element typically only appears in specialized research laboratories, and when it does, it is only for a few seconds.
This element is also classified among a larger group of elements called transuranic elements. These elements are all extremely heavy, with atomic numbers higher than that of uranium. They share the traits of extreme instability and radioactivity, making them frustrating and potentially dangerous to study. Many also do not appear in nature; dubnium is one such example. In order to obtain dubnium, scientists must bombard other elements with charged particles, typically generating isotopes of this element.
Because dubnium has only been synthesized in such small amounts, its chemical properties are not really understood. It is known to be radioactive, and it may share some traits with tantalum. On the periodic table of elements, dubnium is identified with the symbol Db, and this element has an atomic number of 105.
Credit for the discovery of this element is a bit contentious. Researchers at Dubna, a Russian laboratory, claimed to have isolated several isotopes of dubium in 1967, and they proposed their own name for the element, “neilsbohrium.” In 1970, researchers at the University of California, Berkeley, led by Albert Ghiorso, attempted to confirm the Russian discovery. They were not able to replicate the Russian results, but they did manage to isolate several new isotopes of element 105, which they proposed naming “hahnium,” a name which is still sometimes used.
The debate over credit and the honor of naming dragged on until the 1990s, when the International Union of Pure and Applied Chemistry decided to award the credit for discovery jointly to the Russians and the Americans. They also chose the name “dubnium” in honor of the Russian lab; this element is also known as eka-tantalum.
Like other transuranic elements, dubnium represents a potential human health risk because of its radioactivity. For average civilians, this risk is fairly minimal, given that dubnium is not the sort of element one stumbles upon while strolling down the street. Scientists, however, must take precautions when working with dubnium and the elements which are bombarded to create it. Typically access to labs where elements like dubnium is heavily controlled for both health and national security reasons.