Rutherfordium

1 · Identity

Symbol, number

Rf, 104

Oxidation states in water

+4 (book entry, group 4 below hafnium); never measured in water

Note

Identity from the book entry; nothing measured in water.

Sources

Identity

Name and symbol

Rutherfordium, Rf

Atomic number

104 protons

Position

group 4 · period 7 · d-block · transition metal

CAS number

53850-36-5

Atomic structure

Atomic mass

263 u

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d²
[Rn] 7s²⁵f¹⁴⁶d²

Electrons per shell

2, 8, 18, 32, 32, 10, 2

Valence electrons

4 ns and (n-1)d

Physical properties

State at room temperature

Solid

Melting point

2,400 K (2,126.85 °C)

Boiling point

5,800 K (5,526.85 °C)

Density

not in sources

Appearance

not in sources

Thermal conductivity

not in sources

Electrical resistivity

not in sources

Electrical conductivity

not in sources

Crystal structure

hexagonal close-packed

Molar heat capacity

not in sources

Chemical properties

Oxidation states

+4

Electronegativity

not in sources

Ionisation energy

6.02 eV
1st 580 kJ/mol

Electron affinity

not in sources

Atomic radius

not in sources

Ionic radius

not in sources

Reactivity

The first transactinide, made a few atoms at a time; single-atom gas-phase and aqueous experiments show it behaves as a group 4 metal like hafnium, with +4 the only established state, so bulk reactivity cannot be measured.

with water

Not known for the element; in basic solution rutherfordium coprecipitates as a hydroxide, probably Rf(OH)4 (2021 experiment).

with oxygen, air

Not known; the stable refractory oxide RfO2 is predicted by analogy with zirconium and hafnium but has not been made.

with acids

In hydrochloric and hydrofluoric acid single atoms of Rf4+ form hexahalide complexes: $\ce{Rf^4+ + 6 Cl^- -> RfCl6^2-}$, and the analogous RfF6^2-, with a weaker fluoride and sulfate affinity than hafnium.

with halogens

Single atoms react with chlorine and bromine to the volatile tetrahalides RfCl4 and RfBr4, and an oxychloride RfOCl2, RfCl4 being more volatile than HfCl4.

Typical compounds

• RfCl₄ rutherfordium tetrachloride detected in single-atom gas thermochromatography
• RfBr₄ rutherfordium tetrabromide detected in single-atom gas-phase experiments

Occurrence, production and use

Crustal abundance

Not Applicable

Oceanic abundance

Not Applicable

Occurrence and sources

• synthetic only californium-249 bombarded with carbon-12 nuclei

Extraction, production

not in sources

Uses

Due to the small amounts produced and its short half-life, there are currently no uses for rutherfordium outside of basic scientific research.

Safety, toxicity

not in sources

Discovery and name

Discovered by

Joint Institute for Nuclear Research and Lawrence Berkeley National Laboratory

Discovered

1969

First isolated

not in sources

Named by

not in sources

Origin of the name

after Ernest Rutherford

Rutherfordium does not occur naturally in the Earth’s crust. Credit for the first synthesis of this element is given jointly to Albert Ghiorso and his team at the University of California in Berkeley and Georgi Flerov and his team at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The element is named for Ernest Rutherford (Fig. IUPAC.104.1), who won the Nobel Prize for developing the theory of radioactive transformations [645].

Rutherfordium is of interest in particle physics research, but it has no commercial applications. 261Rf was one of the decay products used to confirm the synthesis of copernicium in a particle accelerator experiment [634].

Rutherfordium named after Ernest Rutherford.