A radioactive transuranic element which has been synthesized; SYN. Rf, kurchatovium, Ku, unnilquadium, Unq, element 104, atomic number 104.
Synthesized radioactive element of the transactinide series, atomic number 106, atomic weight 263. It was first synthesized 1974 in the US and given the temporary name unnilhexium. The discovery was not confirmed until 1993. It was officially named 1994 after New Zealand physicist Ernest Rutherford.
The University of California, Berkeley, bombarded californium with oxygen nuclei to get isotope 263; the Joint Institute for Nuclear Research, Dubna, Russia, bombarded lead with chromium nuclei to obtain isotopes 259 and 260.