The first experiments were started in 1976 by a Soviet team led by Y. Oganessian at the Joint Institute for Nuclear Research at Dubna, who produced isotope Bohrium-261. With heavy nuclei of Chromium-54. In this experiment the was performed by bombarding of the fast rotating cylinder coated by a thin layer of Bismuth-204. By a tangentially directed stream of Chromium-54. German scientists have offered name Nielsbohrium.

In 1970 researchers led by Albert Ghiorso at the Berkeley Laboratory of the University of California by bombardment of californium with nitrogen ions and named Hahnium. Also this element was named Nielsbohrium.

Element Molybdenum, Mo, Transition Metal. Comes from the Greek molybdos. Meaning lead and the mineral lead glance. This was confused with molybdenite. All three minerals were previously known as molybdaena. In 1758, Cronstedt presumed that molybdenite. Are different minerals; 20 years late Scheele proved it obtaining Mo. Which he called Wasserbleyerde or molybdenum acid. Is a typical rare element with crustal abundance 1. The main commercial mineral, forming hydrothermal deposits; H.

Element Niobium, Nb, Transition Metal. Main article History of Niobium. After Niobe, daughter of Tantalus in Greek mythology. Main article Occurrence of Niobium. The crustal abundance of Niobium. It occurs in the minerals columbite columbite-tantalite or coltan, pyrochlore and loparite.

Element Tantalum, Ta, Transition Metal. The discovery of transition metal tantalum. Symbolizing oxide is insoluble in acid, and was unable, just as the mythological Tantalos. Ekeberg called the ores in which tantalum. Was discovered tantalite and yttrotantalite. Perhaps Ekeberg isolated impure tantalum. Deep layers and upper mantle are poor by tantalum.

Element Rhenium, Re, Transition Metal. Is the rarest and much dispersed trace element. Its average abundance is 7x10. Is the rarest element with stale isotopes.

In honor the American chemist G. Seaborg was confirmed by IUPAC for the element 106.