Chemical Element: dubnium

(Modern Latin: named after the Joint Institute for Nuclear Research at Dubna, Russia; radioactive metal)

Chemical-Element Information

Symbol: Db
Atomic number: 105
Year discovered: 1967 in Russia and at Berkeley, California.

Discovered by: Workers at the Nuclear Institute at Dubna, Russia; and the University of California, Berkeley, USA.


  • At one time, dubnium had the proposed name of “hahnium” in honor of Otto Hahn (1879-1968), a German physical chemist.
  • Dubna is one of Russia's planned “science cities”, its existence depends on the Joint Institute for Nuclear Research which consists of seven laboratories, employing scientists from many countries.
  • Dubnium apparently was synthesized by Russian and American workers independently by bombardment technologies.
  • Its actual isolation as a free element has not been accomplished.
  • In 1967, Flerov reported element 105 after experiments at the Joint Research Institute in Russia.
  • In 1970, Ghiorso and others announced their synthesis of dubnium at Berkeley, California.
  • This element was previously named, unnilpentium, (Unp) and is the Latin equivalent of “105”; but it was changed because scientists, and others, thought it was too complicated to remember.
  • In addition to unnilpentium (Unp), the proposed names for Element 105 before the official name was chosen by the International Union of Pure and applied Chemistry were hafnium (Ha) and nielsbohrium (Ns).

    • Name in other languages:

    French: dubnium

    German: Dubnium

    Italian: dubnio

    Spanish: dubnio


    Information about other elements may be seen at this Chemical Elements List.

    A special unit about words that include chemo-, chem- may be seen here.