104
  Rf  
261.000000
Rutherfordium

Name: Rutherfordium
Symbol: Rf
Atomic Number: 104
AtomicWeight: 261.000000
Family: Transition Metals
CAS RN: 53850-36-5
Description: A synthetic element not present in nature, appearance unknown, probably metallic solid.
State (25C): Unknown (Synthetic)
Oxidation states: +4
Valence Electrons: 6d27s

Boiling Point:  5800K
Melting Point:
2400K
Electrons Energy Level: 2, 8, 18, 32, 32, 10, 2
Isotopes: 16 + None Stable
Heat of Vaporization: unknown
Heat of Fusion: unknown
Density: unknown
Specific Heat: unknown
Atomic Radius: unknown
Ionic Radius: unknown
Electronegativity: unknown
 

1s2 2s2p6 3s2p6d10 4s2p6d10f14 5s2p6d10f14 6s2p62 7s2

History

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:

22Ne + 242Pu rarrow.gif (63 bytes) 260104 + 4 1n

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.

rutherford.jpg (51228 bytes)

Ernest Rutherford

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.)

Characteristics

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.

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

Isotopes

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.

atom.gif (700 bytes)

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

atom.gif (700 bytes)

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: 5800K
  • Coefficient of Lineal Thermal Expansion/K-1: N/A
  • Conductivity
    Electrical: unknown
    Thermal: 0.23 W/cmK
  • 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: 2400K
  • Physical State (at 20C & 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.

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