Dubnium is a chemical element with symbol Db and atomic number 105. It is named after the town of Dubna in Russia, where it was first produced. Wikipedia


Discovery: In 1967, scientists in Dubna reported the existence of element 105. Their reports were based on finding atoms of some dubnium isotopes using time-coincidence measurements of alpha energies. In late April 1970, they confirmed their findings by synthesizing the element. Around the same time, scientists at the University of California, Berkeley, reported that they too had synthesized element 105. There were also some reports that they had synthesized it in 1969, and others that the Russians’ methods of producing the element could not be duplicated with the same results. Credit for the discovery is still controversial.


Dubnium is a chemical element. It has been named eka-tantalum, hahnium and unnilpentium but is now named dubnium. It has the symbol Db. It has theatomic number 105. It is a very radioactive element that does not exist in nature. It has to be made. The isotope that has the longest half-life only has a half life of 32 hours. Dubnium is a transactinide element.