dubnium (Db), an artificially produced radioactive transuranium element in Group Vb of the periodic table, atomic number 105. The discovery of dubnium (element 105), like that of rutherfordium (element 104), has been a matter of dispute between Soviet and American scientists.
it is only used in research. Dubnium has no known biological role. Dubnium does not occur naturally. It is a transuranium element created by bombarding californium-249 with nitrogen-15 nuclei.
Dubnium is a synthetic chemical element; it has symbol Db and atomic number 105. It is highly radioactive: the most stable known isotope, dubnium-268, has a half-life of about 16 hours. This greatly limits extended research on the element.
The discovery of dubnium is a story of international collaboration and scientific exploration. In 1967, a team of scientists at the Joint Institute for Nuclear Research in Dubna, Russia, bombarded americium atoms with neon ions. They observed evidence of a new element, which they named neilsbohrium in honor of the physicist Niels Bohr.
However, a few years later, a team at the Lawrence Berkeley National Laboratory in California performed a similar experiment and obtained results suggesting the same element. They proposed the name hahnium after Otto Hahn, a Nobel laureate in chemistry.
The debate over the discovery and naming of the element continued for several years. Finally, in 1997, the International Union of Pure and Applied Chemistry (IUPAC) recognized the contributions of both teams and officially named the element dubnium after the city of Dubna, where it was first detected.
Dubnium does not occur naturally. It is a transuranium element created by bombarding californium-249 with nitrogen-15 nuclei.