Rutherfordium (Rf)
transition-metalSolid
Standard Atomic Weight
263 uElectron configuration
[Rn] 7s2 5f14 6d2Melting point
2126.85 °CBoiling point
5526.85 °CDensity
2.33e+4 kg/m³Oxidation states
+3, +4Electronegativity (Pauling)
N/AIonization energy (1st)
6.02 eVDiscovery year
1964Atomic radius
150 pmDetails
Rutherfordium is a synthetic transactinide element and the first member of the 6d transition-metal series. All confirmed isotopes are radioactive and short-lived, so its chemistry is studied atom by atom. Chemical experiments show behavior broadly consistent with a group 4 element, analogous to hafnium and zirconium, with the +4 oxidation state dominant in aqueous and halide systems. Relativistic effects and nuclear instability make direct measurements difficult.
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.
Scientists working at the Joint Institute for Nuclear Research in Dubna, Russia, first reported the production of rutherfordium in 1964. They bombarded atoms of plutonium-242 with ions of neon-22, forming what they believed to be atoms of rutherfordium-260 and four free neutrons. In 1969, a group of scientists working at the Lawrence Radiation Laboratory, now known as the Lawrence Berkeley Laboratory, in Berkeley, California, attempted to confirm the Dubna group's discovery. Lacking the equipment needed to accelerate neon ions, the Berkeley group, led by Albert Ghiorso, bombarded atoms of californium-248 and californium-249 with ions of carbon-12 and carbon-13, producing atoms of rutherfordium-257, rutherfordium-258, rutherfordium-259 and rutherfordium-261. They were, however, unable to produce the same isotope as the Dubna group. Credit for the discovery of rutherfordium is still under debate. Rutherfordium's most stable isotope, rutherfordium-263, has a half-life of about 10 minutes and decays through spontaneous fission.
In 1964, workers at the Joint Nuclear Research Institute at Dubna (U.S.S.R.) bombarded plutonium with accelerated 113 to 115 MeV neon ions. By measuring fission tracks in a special glass with a microscope, they detected an isotope that decays by spontaneous fission. They suggested that this isotope, which had a half-life of 0.3 +/- 0.1 s might be 260-104, produced by the following reaction: 242Pu + 22Ne >260Rf +4n.
Element 104, the first transactinide element, is expected to have chemical properties similar to those of hafnium. It would, for example, form a relatively volatile compound with chlorine (a tetrachloride).
The Soviet scientists have performed experiments aimed at chemical identification, and have attempted to show that the 0.3-s activity is more volatile than that of the relatively nonvolatile actinide trichlorides. This experiment does not fulfill the test of chemically separating the new element from all others, but it provides important evidence for evaluation. Data issued by Soviet scientists reduced the half-life of the isotope they worked with from 0.3 to 0.15 s.
No macroscopic sample of rutherfordium has been prepared, and its visible appearance is unknown. Calculations generally treat it as a very heavy metallic solid under ordinary conditions, but this remains a prediction rather than an observed bulk property.
Rutherfordium has no practical use outside scientific research. It is produced in accelerator experiments to study the limits of the periodic table, transactinide nuclear stability, and the chemistry of single atoms. Individual isotopes have been used in decay-chain identification and in rapid chemical separations designed to compare group 4 behavior with zirconium and hafnium. There is no medical, industrial, structural, or consumer application for the element.
Due to the small amounts produced and its short half-life, there are currently no uses for rutherfordium outside of basic scientific research.
Rutherfordium chemistry has been inferred from very small numbers of atoms in fast gas-phase and aqueous experiments. The most important oxidation state is +4, matching its placement below hafnium. Volatile tetrachloride behavior has been studied for rutherfordium tetrachloride, RfCl₄, in comparison with zirconium tetrachloride, ZrCl₄, and hafnium tetrachloride, HfCl₄. In aqueous solution, hydrolysis, fluoride complexation, and chloride complexation indicate a hard, highly charged cation with group 4 character, although relativistic effects can alter detailed complex stability.
See more information at the Rutherfordium compound page.
The safety concern is radiological rather than chemical toxicity in ordinary handling, because only atom-scale quantities are produced. Hazards depend on the isotope and its decay products; many known isotopes decay by alpha emission, spontaneous fission, or both. Accelerator targets, collection systems, and contaminated apparatus require radiological controls, but rutherfordium itself is not encountered by the public or in commerce.
Rutherfordium has no confirmed natural environmental occurrence. Any atoms made in laboratories decay rapidly and are produced in quantities far too small to form an environmental reservoir or chemical cycle. Its environmental behavior as a bulk substance is therefore unobserved; only its predicted or atom-at-a-time chemical interactions can be compared with those of other group 4 metals.
Rutherfordium has no commodity market, no stockpiled supply, and no economic demand. Production requires heavy-ion accelerators, specialized targets, and rapid detection systems, yielding atoms or very small numbers of atoms for immediate study. Isotopes are made by nuclear reactions such as bombarding actinide targets with lighter ions, and the practical constraint is experimental access rather than raw-material value. Recycling and substitution are not relevant except in the general sense that other elements are used whenever a stable material is needed.
Made by bombarding californium-249 with beams of carbon-12 and 13, which produced an isotope with half lives of 4+ and 3 sec.
Rutherfordium is not expected to be a persistent cosmic element. Its known isotopes have half-lives far too short for primordial survival, and any atoms formed in extreme astrophysical nucleosynthesis would decay quickly into lighter nuclei. No extraterrestrial reservoir is known, and its significance in the universe is chiefly as a laboratory probe of very heavy nuclei.
- Rutherfordium was central to early naming disputes over the first transactinide elements.
- Its chemistry must often be completed before the atom decays.
- Gas-phase studies have compared RfCl₄ with the tetrachlorides of zirconium and hafnium.
- Some rutherfordium isotopes are identified through linked alpha-decay chains.
- The element is named for Ernest Rutherford.
Images
Properties
Physical
- Atomic radius (empirical)
- 150 pm Compare Atomic radius (empirical) of all elements →
- Density
- 2.33 × 104 kg/m³ Compare Density of all elements →
- Phase at STP
- Solid Compare Phase at STP of all elements →
- Melting point
- 2126.85 °C Compare Melting point of all elements →
- Boiling point
- 5526.85 °C Compare Boiling point of all elements →
Chemical
- Electron affinity
- 0.65 eV
- Ionization energy (1st)
- 6.02 eV Compare Ionization energy (1st) of all elements →
- Ionization energy (2nd)
- 14.350049 eV Compare Ionization energy (2nd) of all elements →
- Ionization energy (3rd)
- 23.840082 eV Compare Ionization energy (3rd) of all elements →
- Ionization energy (4th)
- 31.87011 eV Compare Ionization energy (4th) of all elements →
- Ionization energy (5th)
- 64.00022 eV Compare Ionization energy (5th) of all elements →
- Oxidation states
- +3, +4 Compare Oxidation states of all elements →
- Valence electrons
- 4 Compare Valence electrons of all elements →
- Electron configuration
- [Rn] 7s2 5f14 6d2
Thermodynamic
N/A
Nuclear
- Protons
- 104 Compare Protons of all elements →
- Neutrons
- 162 Compare Neutrons of all elements →
- Known isotopes
- 16 Compare Known isotopes of all elements →
- Stable isotopes
- 0 Compare Stable isotopes of all elements →
- Mass number (most stable)
- 267
- Most stable isotope
- Rf-266
- Discovery year
- 1964
Abundance
N/A
Crystal Structure
N/A
Electronic Structure
- Electrons per shell
- 2, 8, 18, 32, 32, 10, 2 Compare Electrons per shell of all elements →
Identifiers
- CAS number
- 53850-36-5 Compare CAS number of all elements →
- Term symbol
- 3F2
- InChI
- InChI=1S/Rf
- InChI Key
- YGPLJIIQQIDVFJ-UHFFFAOYSA-N
Electron Configuration Predicted
Rf: 5f¹⁴ 6d² 7s²[Rn] 5f¹⁴ 6d² 7s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁶ 5f¹⁴ 6d² 7s²Atomic model
Isotopes change neutron count, mass, and stability — not the electron configuration of a neutral atom.
Schematic atomic model, not to scale.
Atomic Fingerprint
Emission / Absorption Spectrum
Isotope Distribution
No stable isotopes.
| Mass number | Atomic mass (u) | Natural abundance | Half-life |
|---|---|---|---|
| 262 Radioactive | 262.10992 ± 0.00024 | N/A | 250 ms |
| 254 Radioactive | 254.10005 ± 0.0003 | N/A | 22.9 us |
| 260 Radioactive | 260.10644 ± 0.00022 | N/A | 21 ms |
| 253 Radioactive | 253.10044 ± 0.00044 | N/A | 13 ms |
| 258 Radioactive | 258.103428 ± 0.000034 | N/A | 12.5 ms |
Phase / State
Reason: 2101.8 °C below melting point (2126.85 °C)
Schematic, not to scale
Phase transition points
Density
At standard conditions
At standard conditions
Atomic Spectra
Showing 10 of 93. Sorted by ion charge (ascending).
Levels Holdings ?
| Ion | Charge | Levels |
|---|---|---|
| Rf I | 0 | 2 |
| Rf II | +1 | 2 |
| Rf III | +2 | 2 |
| Rf IV | +3 | 2 |
| Rf V | +4 | 2 |
| Rf VI | +5 | 2 |
| Rf VII | +6 | 2 |
| Rf VIII | +7 | 2 |
| Rf IX | +8 | 2 |
| Rf X | +9 | 2 |
Crystal structure data not available
Compounds
Isotopes (5)
In 1969 Ghiorso, Nurmia, Harris, K.A.Y. Eskola, and P.L. Eskola of the University of California at Berkeley reported that they had positively identified two, and possibly three isotopes of Element 104. The group indicated that, after repeated attempts, they produced isotope 260104 reported by the Dubna groups in 1964.
| Mass number | Atomic mass (u) | Natural abundance | Half-life | Decay mode | |
|---|---|---|---|---|---|
| 262 Radioactive | 262.10992 ± 0.00024 | N/A | 250 ms | SF ≈100% | |
| 254 Radioactive | 254.10005 ± 0.0003 | N/A | 22.9 us | SF ≈100%α<1.5% | |
| 260 Radioactive | 260.10644 ± 0.00022 | N/A | 21 ms | SF ≈100%α ?β+ ? | |
| 253 Radioactive | 253.10044 ± 0.00044 | N/A | 13 ms | SF ≈100%α ? | |
| 258 Radioactive | 258.103428 ± 0.000034 | N/A | 12.5 ms | SF =95.1±1.6%α =4.9±1.6% |
Extended Properties
Covalent Radii (Extended)
- Covalent radius (Pyykkö)
- 157 pm
- Covalent radius (Pyykkö, double)
- 140 pm
- Covalent radius (Pyykkö, triple)
- 131 pm
Numbering Scales
- Mendeleev
- 46
Polarizability & Dispersion
- Dipole polarizability
- 112 a.u.
- Dipole polarizability (unc.)
- 10 a.u.
Oxidation State Categories
Advanced Reference Data
Isotope Decay Modes (33)
| Isotope | Mode | Intensity |
|---|---|---|
| 253 | SF | 100% |
| 253 | A | — |
| 254 | SF | 100% |
| 254 | A | 1.5% |
| 255 | A | 52.8% |
| 255 | SF | 47.2% |
| 255 | B+ | 6% |
| 256 | SF | 99.7% |
| 256 | A | 0.3% |
| 257 | A | 89.3% |
Additional Data
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
Not Applicable
References (1)
- [5] Rutherfordium https://education.jlab.org/itselemental/ele104.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
Not Applicable
References (1)
- [5] Rutherfordium https://education.jlab.org/itselemental/ele104.html
References
(8)
Data deposited in or computed by PubChem
The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.
Element data are cited from the Atomic weights of the elements (an IUPAC Technical Report). The IUPAC periodic table of elements can be found at https://iupac.org/what-we-do/periodic-table-of-elements/. Additional information can be found within IUPAC publication doi:10.1515/pac-2015-0703 Copyright © 2020 International Union of Pure and Applied Chemistry.
The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.
Thomas Jefferson National Accelerator Facility (Jefferson Lab) is one of 17 national laboratories funded by the U.S. Department of Energy. The lab's primary mission is to conduct basic research of the atom's nucleus using the lab's unique particle accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF). For more information visit https://www.jlab.org/
The periodic table at the LANL (Los Alamos National Laboratory) contains basic element information together with the history, source, properties, use, handling and more. The provenance data may be found from the link under the source name.
The periodic table contains NIST's critically-evaluated data on atomic properties of the elements. The provenance data that include data for atomic spectroscopy, X-ray and gamma ray, radiation dosimetry, nuclear physics, and condensed matter physics may be found from the link under the source name. Ref: https://www.nist.gov/pml/atomic-spectra-database
This section provides all form of data related to element Rutherfordium.