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Known properties
Name, Symbol, NumberRutherfordium, Rf, 104
Chemical series Transition metals
Group, Period, Block4, 7 , d
Appearance unknown; probably metallic,
silvery white or gray
Atomic weight [261] amu
Electron configuration probably [Rn]55f14 6d2 7s2
e- 's per energy level2,8,18,32,32,10,2
State of matter Presumably a solid

Rutherfordium is a chemical element in the periodic table that has the symbol Rf and atomic number 104. This is a highly radioactive synthetic element whose most stable isotope has a half life of less than 70 seconds. This element therefore is not used for anything and little is known about it. Rutherfordium is the first transactinide element and it is predicted to have chemical properties similar to hafnium.


Rutherfordium (named in honor of Ernest Rutherford) was reportedly first synthesized in 1964 at the Joint Nuclear Research Institute at Dubna (U.S.S.R). Researches there bombarded plutonium with accelerated 113 to 115 MeV neon ions and claimed that they detected nuclear fission tracks in a special type of glass with a microscope which indicated the presence of a new element.

In 1969 researchers at the University of California, Berkeley synthesized the element by subjecting californium-249 and carbon-12 to high energy collisions. The UC group also stated that they could not reproduce the earlier synthesis by Soviet scientists.

This resulted in an element naming controversy; Since the Soviets claimed that it was first detected in Dubna, Dubium (Db) was suggested, as was Kurchatovium and symbol Ku for element 104, in honor of Igor Vasilevich Kurchatov (1903-1960), former Head of Soviet Nuclear Research. The Americans, however, proposed Rutherfordium (symbol Rf) for the new element to honor Ernest Rutherford, a noted nuclear physicist from New Zealand. The International Union of Pure and Applied Physics (IUPAC) adopted Unnilquadium (symbol Unq) as a temporary name for this element. However in 1997 they resolved the dispute and adopted the current name.

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