Rutherfordium (Rf)

Rutherfordium (symbol Rf) is the chemical element with atomic number 104: a transition metal, radioactive, made artificially, with an atomic mass of 267 u. Discovered in 1964 (Dubna and Berkeley laboratories).

Rutherfordium is the first of the so-called transactinide or superheavy elements, which come after the actinides. It was claimed by both the Soviets in Dubna and the Americans in Berkeley, each with their own name, fueling thirty years of “Transfermium Wars.” Very little is known about it, other than that it behaves chemically like hafnium. Its most stable isotope, rutherfordium-267, has a half-life of around an hour.

Key facts

Atomic number: 104
Symbol: Rf
French name: Rutherfordium
Atomic mass: 267 u
Molar mass: [267] g/mol
Family: Transition metals
Position: period 7, group 4, d-block
State at 0 °C: Unknown
First ionization energy: 580 kJ/mol
Electron configuration: [Rn] 5f¹⁴ 6d² 7s²
Radioactive: yes
Discovery: 1964, Dubna and Berkeley laboratories

Origin of the name

In honor of the physicist Ernest Rutherford.

What does rutherfordium look like?

Never observed in visible amounts; predicted to be a dense, silvery metal.

Where is rutherfordium found?

Absent from nature.

How is rutherfordium produced?

It is made by fusing nuclei in a particle accelerator: a beam of ions (atomic nuclei fired at very high speed) is aimed at a heavy target. Dubna used neon on plutonium, Berkeley carbon on californium. Only a few atoms form in each experiment.

Top producers

Russia (Dubna)
United States (Berkeley)

What is rutherfordium used for?

Basic research only
Studying the chemistry of superheavy elements

In everyday life

None — it exists only for moments in the lab

Role in living things

No biological role.

Hazards of rutherfordium

Radioactive, but produced atom by atom: no practical danger.

Cosmic origin

Human-made: Does not exist (or barely) in nature: synthesized in a reactor or accelerator.

History of rutherfordium

In 1964, Georgy Flerov's team in Dubna (Joint Institute for Nuclear Research, USSR) announced element 104 and proposed “kurchatovium,” in honor of the father of the Soviet bomb. In 1969, Albert Ghiorso at Berkeley challenged those results and proposed “rutherfordium.” The International Union of Pure and Applied Chemistry (IUPAC) settled the matter in 1997 in favor of rutherfordium, honoring Ernest Rutherford, discoverer of the atomic nucleus.

Did you know?

As early as 1966, Czech chemist Ivo Zvára in Dubna studied its chemistry by sending its atoms through a gas, showing that it resembles hafnium.
For years, American and Soviet textbooks used different names for this element.
Rutherford, its namesake, had himself carried out the first artificial transmutation of an element in 1919.

Isotopes of rutherfordium

No stable isotopes; rutherfordium isotopes live anywhere from a few milliseconds to about an hour.

rutherfordium-261: radioactive, half-life 1.13 min. The one most used to study the element's chemistry.
rutherfordium-267: radioactive, half-life 1.3 h. The longest-lived known.

Related elements

Same family (transition metals): Scandium (Sc), Titanium (Ti), Vanadium (V), Chromium (Cr), Manganese (Mn), Iron (Fe), Cobalt (Co), Nickel (Ni), Copper (Cu), Zinc (Zn), Yttrium (Y), Zirconium (Zr), Niobium (Nb), Molybdenum (Mo), Technetium (Tc), Ruthenium (Ru), Rhodium (Rh), Palladium (Pd), Silver (Ag), Cadmium (Cd), Hafnium (Hf), Tantalum (Ta), Tungsten (W), Rhenium (Re), Osmium (Os), Iridium (Ir), Platinum (Pt), Gold (Au), Mercury (Hg), Dubnium (Db), Seaborgium (Sg), Bohrium (Bh), Hassium (Hs).

Same column (group 4): Titanium (Ti), Zirconium (Zr), Hafnium (Hf).