Rutherfordium
Transition metal · Period 7 · Group 4 · d-block
The first transactinide, and the start of a naming war
- Atomic mass
- 267 u
- State at 25 °C
- Solid
- Electronegativity
- —
- Melting point
- 2,126.9 °Cpredicted
- Boiling point
- 5,526.9 °Cpredicted
- Configuration
- [Rn] 5f14 6d2 7s2
Nucleus drawn at reduced count for clarity. Drag to rotate.
Rutherfordium, explained
Video lesson in production
Bhavya’s explainer for this element will play here.
Overview
Rutherfordium is the first element after the actinides, opening the 6d transition series in group 4 under titanium, zirconium and hafnium. Its ground-state configuration is predicted to be 7s2 6d2, and experiments confirm it behaves mainly as a +4 element. Gas-phase studies show it forms a volatile tetrachloride, RfCl4, like ZrCl4 and HfCl4, and in aqueous solution Rf4+ forms fluoride and chloride complexes broadly similar to those of hafnium.
The details differ in measurable ways. Relativistic effects, which pull in s orbitals and expand d orbitals in heavy atoms, shift rutherfordium's complex-forming strength and volatility so that it does not always mirror hafnium exactly. Its longest-lived known isotope, rutherfordium-267, has a half-life of roughly an hour, but production rates of a few atoms per hour mean every result comes from repeating fast experiments thousands of times.
Discovery
In 1964 Georgy Flerov's team at Dubna reported element 104 from neon-22 bombardment of plutonium-242 and proposed the name kurchatovium. In 1969 Albert Ghiorso's group at Berkeley produced it from californium-249 and carbon-12, disputed Dubna's data, and proposed rutherfordium after Ernest Rutherford. The quarrel was part of the Transfermium Wars. IUPAC credited both labs and settled on rutherfordium in 1997.
- Where it’s found
- Rutherfordium does not occur in nature; it is made in accelerators by fusing light ions with actinide targets such as californium or curium.
- What it’s used for
- Atom-at-a-time chemistry
- Relativistic effects research
- Testing group 4 trends
- Nuclear structure research
- In living things
- Rutherfordium has no biological role; it is radioactive and exists only as individual atoms in laboratories.
- Safety
- Radioactive and made only a few atoms at a time; it decays within minutes to hours.
How it compares
Where Rutherfordium sits among all 118 elements on the trends that shape the table.
- ElectronegativityNo data
Not measured for this element
- Ionization energy580kJ/mol
#78 of 104 elements with data · predicted
- Atomic radiusNo data
Not measured for this element
- Electron affinityNo data
Not measured for this element
- Density23.2g/cm³
#8 of 114 elements with data · predicted
- Melting point2,400K
#12 of 110 elements with data · predicted
- Density
- 23.2 g/cm³
- Atomic radius
- —
- Covalent radius
- —
- Molar heat
- —
- Appearance
- —
- Discovered by
- Joint Institute for Nuclear Research
Inside the atom
104 electrons arranged in 7 shells: 2 · 8 · 18 · 32 · 32 · 10 · 2.
Orbital diagram
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d2 · shorthand [Rn] 5f14 6d2 7s2
- 1s2
- 2s2
- 2p6
- 3s2
- 3p6
- 4s2
- 3d10
- 4p6
- 5s2
- 4d10
- 5p6
- 6s2
- 4f14
- 5d10
- 6p6
- 7s2
- 5f14
- 6d2
Each box is an orbital holding up to two electrons of opposite spin. Highlighted subshells hold the valence electrons that decide how Rutherfordium bonds.
Signature reactions
How the first atoms were made, and how they fall apart.
Nuclear · Fusion-evaporation
Berkeley synthesis
Carbon-12 fuses with californium-249 and the compound nucleus boils off four neutrons. Ghiorso's team linked the alpha decays of rutherfordium-257 to its known nobelium-253 daughter, a convincing proof of identity.
Conditions: carbon-12 beam on californium-249, Berkeley HILAC, 1969
Nuclear · Fusion-evaporation
Dubna synthesis
Dubna's first claim rested on spontaneous-fission events assigned to rutherfordium-260 from this reaction. The assignment was later questioned, but continued Dubna work helped earn shared discovery credit.
Conditions: neon-22 beam on plutonium-242, Dubna, 1964
Synthesis · Gas-phase chlorination
Formation of rutherfordium tetrachloride
Atoms swept into a chlorine-containing gas stream form RfCl4, whose volatility was compared with ZrCl4 and HfCl4 in heated columns. These measurements showed rutherfordium behaves as a group 4 element, as the periodic table predicts.
Conditions: single atoms in a chlorinating carrier gas, thermochromatography
Where you’ll meet it
Ernest Rutherford
The New Zealand-born physicist who discovered the atomic nucleus is honored by element 104.
Photo: Wikimedia Commons
Rutherford scattering experiments
The gold-foil experiments revealed the nucleus that superheavy-element makers now fuse together.
Photo: Wikimedia Commons
Zirconium
Rutherfordium's volatile chloride and solution complexes are benchmarked against those of zirconium and hafnium in group 4.
Photo: Wikimedia Commons
Joint Institute for Nuclear Research
Dubna made the first claim to element 104 in 1964 and shares credit for its discovery.
Photo: Wikimedia Commons
Research
No research on Rutherfordium yet
When Bhavya publishes a project that studies Rutherfordium, it will be linked here.