Rutherfordium

Rutherfordium (named in honour of noted New Zealand nuclear physicist Ernest Rutherford) was reportedly first synthesized in 1964. Workers of the Joint Nuclear Research Institute at Dubna (U.S.S.R.) bombarded plutonium, ²⁴²Pu, with accelerated 113 to 115 MeV ²²Ne ions. By measuring fission tracks in a special glass with a microscope, they claimed detection of an isotope that decays by spontaneous fission. They reported this isotope to possibly be ²⁶⁰104 with a half-life of 0.3 +/- 0.1 seconds, produced by the following reaction:

In 1969, Albert Ghiorso, Nurmia, Harris, K. A. Y. Eskola, and P. L. Eskola of the University of California at Berkeley reported they had positively identified two, and possibly three, isotopes of Element 104. The group also indicated that after repeated they had been unable to produce isotope ²⁶⁰104 reported by the Dubna groups in 1964. The discoveries at Berkeley were made by bombarding a target of ²⁴⁹Cf With ¹²C nuclei of 71 MeV, and ¹³C nuclei of 69 MeV. The combination of ¹²C with ²⁴⁹Cf followed by instant emission of four neutrons produced Element ²⁵⁷104. This isotope has a half-life of 4 to 5 s, decaying by emitting an alpha particle into ²⁵³No, with a half-life of 105 s. The same reaction, except with the emission of three neutrons, was thought to have produced ²⁵⁸104 with a half-life of about 1/100 s. Element ²⁵⁹104 is formed by the merging of a ¹³C nuclei with ²⁴⁹Cf, followed by emission of three neutrons. This isotope has a half-life of 3 to 4 s, and decays by emitting an alpha particle into ²⁵⁵No, which has a half-life of 185 seconds. Thousands of atoms of ²⁵⁷104 and ²⁵⁹104 have been detected. The Berkeley group believe their identification of ²⁵⁸104 was correct. As of January 1995 it was thought that eleven isotopes of Element 104 had been identified. The Berkeley group proposed for the new element the name Rutherfordium (symbol Rf), in honor of Ernest Rutherford, New Zealand physicist who is known as the "father" of nuclear physics.

This resulted in an element naming controversy; since the Soviets claimed that it was first detected in Dubna, dubnium (Db) was suggested, as was kurchatovium (symbol Ku) for element 104, in honor of Igor Vasilevich Kurchativ (1903 - 1960), late head of Soviet nuclear research. The International Union of Pure and Applied Chemistry (IUPAC) adopted unnilquadium (symbol Unq) as a temporary, systematic element name, derived from the Latin names for digits 1, 0, and 4. However in 1997 they resolved the dispute and adopted the current name. (Element 105 was named Dubnium, instead.)

Rutherfordium, 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 seconds 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. New data, reportedly issued by Soviet scientists; have reduced the half-life of the isotope they worked with from 0.3 to 0.15 seconds.

This is a highly radioactive synthetic element whose most stable isotope is ²⁶⁵Rf with a half-life of approximately 13 hours.

This element therefore has no applications and little is known about it. Rutherfordium is the first transactinide element and it is predicted to have chemical properties similar to hafnium.

Only very small amounts of of element 104, Rutherfordium, have ever been made. The first samples were made through nuclear reactions involving fusion of an isotope of plutonium, ²⁴²Pu, with one of neon, ²²Ne.

Isotope	Atomic Mass	Half-Life
Rf253	253.101	~1.8 seconds
Rf254	254.1	0.5 ms
Rf255	255.101	1.5 seconds
Rf256	256.1012	6.7 ms
Rf257	257.103	4.7 seconds
Rf258	258.104	12 ms
Rf259	259.1056	3.1 seconds
Rf260	260.106	20.1 ms
Rf261	261.109	65 seconds
Rf262	262.11	2.1 seconds
Rf263	263.113	10 minutes
Rf264	264.114	~1 hour
Rf265	265.117	13 hours
Rf266	266.118	~10 hours
Rf267	267.122	~5 hours
Rf268	268.124	~1 hours

Rutherfordium Data

Atomic Structure

Atomic Radius: unknown
Atomic Volume: unknown
Covalent Radius: unknown
Cross Section (Thermal Neutron Capture) Barns: unknown
Crystal Structure: unknown
Electron Configuration:
1s² 2s²p⁶ 3s²p⁶d¹⁰ 4s²p⁶d¹⁰f¹⁴ 5s²p⁶d¹⁰f¹⁴ 6s²p⁶² 7s²
Electrons per Energy Level: 2, 8, 18, 32, 32, 10, 2
Ionic Radius: unknown
Filling Orbital: unknown
Number of Electrons: 104
Number of Neutrons (most common/stable nuclide): 157
Number of Protons: 104
Oxidation States: +4
Valence Electrons: 6d² 7s²

Chemical Properties

Electrochemical Equivalent: unknown
Electron Work Function: unknown
Electronegativity: N/A (Pauling); N/A (Allrod Rochow)
Heat of Fusion: kJ/mol
Incompatibilities: unknown
Ionization Potential
- First: unknown
Valence Electron Potential (-eV): unknown

Physical Properties

Atomic Mass Average: 261
Boiling Point: 5800°K
Coefficient of Lineal Thermal Expansion/K^-1: N/A
Conductivity

Electrical: unknown
Thermal: 0.23 W/cm°K
Description:

A man made radioactive element and the first transactinide element.
Flammablity Class:
Freezing Point: see melting point
Heat of Vaporization: kJ/mol
Melting Point: 2400°K
Physical State (at 20°C & 1atm):
Specific Heat: unknown

Regulatory / Health

CAS Number
- 53850-36-5
NFPA 704
- Health:
- Fire:
- Reactivity:
- Special Hazard: Radioactive<
- OSHA Permissible Exposure Limit (PEL)
  - No limits set by OSHA
- OSHA PEL Vacated 1989
  - No limits set by OSHA
- NIOSH Recommended Exposure Limit (REL)
  - No limits set by NIOSH
- Levels In Humans:
  Note: this data represents naturally occuring levels of elements in the typical human, it DOES NOT represent recommended daily allowances.
  - Blood/mg dm^-3: nil
  - Bone/p.p.m: nil
  - Liver/p.p.m: nil
  - Muscle/p.p.m: nil
  - Daily Dietary Intake: nil
  - Total Mass In Avg. 70kg human: nil
Who / Where / When / How
- Discoverer: A. Ghiorso, Nurmia, Harris, K.A.Y. Eskola, and P.L. Eskola
- Discovery Location: Berkeley California
- Discovery Year: 1969
- Name Origin:
  
  In honor of Lord Ernest R. Rutherford, a New Zealand physicist and chemist
- Abundance:
  - Earth's Crust/p.p.m.: nil
  - Seawater/p.p.m.: nil
  - Atmosphere/p.p.m.: nil
  - Sun (Relative to H=1E¹²): N/A
- Sources:
  
  Bombarding plutonium with accelerated 113 to 115 MeV neon ions. Also by bombarding a target of Cf249 with C12 nuclei of 71 MeV, and C13 nuclei of 69 MeV. Only several thousand atoms of this element have been produced.
- Uses:
  
  This element is of research interest only.
- Additional Notes:
  
  Evidence of element 104 was first detected at the Joint Nuclear Research Institute at Dubna (USSR) in 1964 by bombarding plutonium with accelerated 113 to 115 MeV neon ions. By measuring fission tracks in a special glass with a microscope, the scientists detected an isotope that decays by spontaneous fission. The isotope was thought to be Rf260 with a half life of 0.15 to 0.3 seconds. It was not until 1969, however that the group in Berkley were able to chemically separate element 104 and positively identified two possibly three isotopes of the element. The detection vs. chemical isolation of this element caused a dispute as to who really discovered this element. This dispute was settled in 1992 by the IUPAC when they concluded that credit for the discovery should be shared between the Russian and American scientists. In August of 1997 the International Union of Pure and Applied Chemistry announced the official naming of this element as Rutherfordium with the atomic symbol of Rf. The IUPAC choose Rutherfordium over the Russians' choice of Kurchatovium, which was in honor of Igor Vasilevich Kurchatov (1903-1960), former Head of Soviet Nuclear Research.

1s²
2s²	2p⁶
3s²	3p⁶	3d¹⁰
4s²	4p⁶	4d¹⁰	4f¹⁴
5s²	5p⁶	5d¹⁰	5f¹⁴
6s²	6p⁶	6d²
7s²

Transition Metals
Group	3 (IIIB)	4 (IVB)	5 (VB)	6 (VIB)	7 (VIIB)	8 (VIIIB)	9 (VIIIB)	10 (VIIIB)	11 (IB)	12 (IIB)
Period 4	21 Sc 44.95	22 Ti 47.86	23 V 50.94	24 Cr 51.99	25 Mn 54.93	26 Fe 55.84	27 Co 58.93	28 Ni 58.69	29 Cu 63.54	30 Zn 65.39
Period 5	39 Y 88.90	40 Zr 91.22	41 Nb 92.90	42 Mo 95.94	43 Tc 98.00	44 Ru 101.0	45 Rh 102.9	46 Pd 106.4	47 Ag 107.8	48 Cd 112.4
Period 6	57 La 138.9	72 Hf 178.4	73 Ta 180.9	74 W 183.8	75 Re 186.2	76 Os 190.2	77 Ir 192.2	78 Pt 195.0	79 Au 196.9	80 Hg 200.5
Period 7	89 Ac 227.0	104 Rf 261.0	105 Db 262.0	106 Sg 266.0	107 Bh 264.0	108 Hs 269.0	109 Mt 268.0	110 Ds 269.0	111 Rg 272.0	112 Uub 277.0