Dubnium, like its neighbour rutherfordium, was the subject of competing discovery claims from Dubna and Berkeley in the 1960s and 1970s, and of a long naming dispute. The compromise name adopted in 1997 honours Dubna, the Russian town whose Joint Institute for Nuclear Research had played a leading part in creating the heaviest elements. Dubnium is an intensely radioactive synthetic metal, studied only in fleeting traces. Its longest-lived isotope survives about a day, and it is made only a few atoms at a time; chemical experiments on those atoms place it, as expected, alongside tantalum and niobium in group five, though relativistic effects lend its behaviour some surprises.
The rival Dubna and Berkeley teams had in fact used different nuclear reactions to reach element 105, Dubna fusing americium with neon ions and Berkeley bombarding californium with nitrogen ions, a genuine methodological difference that made comparing and verifying each other's results unusually difficult and contributed directly to the long dispute over who could rightfully claim priority. Modern production techniques have since converged on more reliable methods, though dubnium remains, like its neighbours, obtainable only a handful of atoms at a time.