Rutherfordium (Rf)

Rutherfordium is a synthetic radioactive chemical element with the atomic number 104 in the periodic table. It cannot be found in Earth’s crust since it was produced in a scientific laboratory. According to the chemical calculations, rutherfordium would be a member of the titanium family of the periodic table. The elements in this group are also classified as hard refractory metals. 

Fact Box

Chemical and Physical Properties of Rutherfordium

The symbol in the periodic table of elements: Rf

Atomic number: 104

Atomic weight (mass): 260.9 g.mol-1

Group number: 4

Period: 7 (d-block)

Color: N/A

Physical state: Solid at room temperature

Half-life: From 13(5) milliseconds to 2.5 hours

Electronegativity according to Pauling: Unknown

Density: (Assumed) 23

Melting point: (Assumed) 2100oC

Boiling point: (Assumed) 5500oC

Van der Waals radius: Unknown

Ionic radius: Unknown

Isotopes: 17

Most characteristic isotope: 265Rf

Electronic shell: [Rn] 5f146d27s2

The energy of the first ionization: N/A

The energy of the second ionization: N/A

Discovery date: In 1964 by Georgy Flerov and colleagues (Russia/Soviet Union), and independently by Albert Ghiorso and colleagues (United States)

With the periodic table symbol Rf, atomic number 104, atomic mass of 260.9 g.mol-1, and electron configuration [Rn] 5f146d27s2, rutherfordium is a radioactive transuranium synthetic element. Both the physical and chemical properties of element 106 are subject to chemical calculations because there are only a few atoms of this radioactive substance produced so far. It’s assumed that rutherfordium could resemble the elements of Group 4, which includes titanium (Ti), zirconium (Zr), and hafnium (Hf). The atomic radius for rutherfordium is expected to be around 150 pm. 

How Was Rutherfordium Discovered?

In 1964, the team of scientists employed at The Joint Institute for Nuclear Research in Dubna, Russia, tried to synthesize the transuranium element with the atomic number 104. For this, the team led by Georgy Flerov employed the hot fusion reaction of neon-22 projectiles with plutonium-242 targets. After bombarding plutonium-242 with ions of neon-22, the team of Soviet discoverers claimed to have produced the isotope 260 of the new transuranium element.

Nearly at the same time, the American team of researchers led by Albert Ghiorso had to use less sophisticated equipment in an effort to reproduce the experiment of the Russan team. For this, Ghiroso and his colleagues at the University of California, Berkeley, United States, attempted a bombardment of californium-249 with ions of carbon-12 and carbon-13 due to the lack of an neon ion accelerator. The result of the chemical experiment conducted by the American team was production of two isotopes of element 104, 257Rf, 259Rf, and 261Rf.

Despite being the first team to produce any isotope of element 104, the success achieved by the Dubna team of researchers was overshadowed by the results of the American team from the Lawrence Berkeley laboratory. Maybe they didn’t manage to confirm the scientific finding of the Dubna group, but they certainly succeeded in producing more isotopes of the new element. 

How Did Rutherfordium Get Its Name?

The temporary name of element 104 was Unnilquadium, with the symbol Unq. In Latin, unnilquadium translates to the atomic number of the element ‘one-zero-four’. 

Its official name ‘rutherfordium’ was assigned by the International Union of Pure and Applied Chemistry in August, 1997. This name was chosen over the Russian’s choice of ‘kurchatovium’, in honor of the former Head of Soviet Nuclear Research, Igor Vasilevich Kurchatov (1903-1960). 

The name ‘rutherfordium’ was decided on by IUPAC after the suggestion of the American team of scientists, who wanted to honor the accomplishments of the British-New Zealand chemist and researcher Ernest Rutherford (1871-1937). 

Where Can You Find Rutherfordium?

Rutherfordium cannot be found in nature since it is a synthetic transuranium element produced in small amounts at specially equipped scientific laboratories. Atoms of element 104 can be produced and worked with only in strictly controlled conditions of nuclear institutes. 

Rutherfordium in Everyday Life

Beyond scientific purposes, there is no other practical application of this radioactive transuranium chemical element. 

How Dangerous Is Rutherfordium?

Ruthetherfordium’s radioactivity would be considered an extreme hazard affecting all life forms and environmental systems, provided there are larger quantities and a bigger exposure. 

Environmental Effects of Rutherfordium

Due to the unstable nature and extremely short half-life of the isotopes of rutherfordium, the environmental effects of this chemical element cannot be considered.  

Isotopes of Rutherfordium

There are 17 isotopes of rutherfordium with an atomic weight ranging from 253Rf to 270Rf. Since Rf is a radioactive transuranium element, it has no stable isotopes. With a half-life of 2.5 hours, 267Rf is the longest living form of element 104. Alpha decay and spontaneous fission are the primary decay modes of the rutherfordium isotopes. 



[n 1]

ZNIsotopic mass (Da)


[n 2][n 3]



[n 4]




[n 5]




Spin and



[n 6][n 4]

Excitation energy[n 4]
253Rf104149253.10044(44)#13(5) msSF (51%)(various)(7/2)(+#)
α (49%)249No
254Rf104150254.10005(30)#23(3) µsSF (99.7%)(various)0+
α (.3%)250No
255Rf104151255.10127(12)#1.64(11) sSF (52%)(various)(9/2−)#
α (48%)251No
256Rf104152256.101152(19)6.45(14) msSF (96%)(various)0+
α (6%)252No
257Rf104153257.102918(12)#4.7(3) sα (79%)253No(1/2+)
β+ (18%)257Lr
SF (2.4%)(various)
258Rf104154258.10343(3)12(2) msSF (87%)(various)0+
α (13%)254No
259Rf104155259.10560(8)#2.8(4) sα (93%)255No7/2+#
SF (7%)(various)
β+ (.3%)259Lr
260Rf104156260.10644(22)#21(1) msSF (98%)(various)0+
α (2%)256No
261Rf104157261.10877(5)68 s[3]α (76%)257No9/2+#
β+ (14%)261Lr
SF (10%)(various)
262Rf104158262.10993(24)#2.3(4) sSF (99.2%)(various)0+
α (.8%)258No
263Rf104159263.1125(2)#11(3) minSF (70%)(various)3/2+#
α (30%)259No
265Rf[n 7]104161265.11668(39)#1.1 min[2]SF(various) 
266Rf[n 8][n 9]104162266.11817(50)#23 s#[5][6]SF(various)0+
267Rf[n 10]104163267.12179(62)#2.5 hSF(various)13/2−#
268Rf[n 8][n 11]104164268.12397(77)#1.4 s#[6][7]SF(various)0+
270Rf[8][n 8][n 12]104166 20 ms#[6][9]SF(various)0+

Source: Wikipedia

List of Rutherfordium Compounds 

Element 104 is assumed to have a close-packed hexagonal crystal structure. In a compound, rutherfordium would mostly adopt the oxidation states of +2, +3, and +4. 

5 Interesting Facts and Explanations

  1. Rutherfordium is the first transactinide element to be discovered by means of nuclear fusion reaction. The second super-heavy element discovered after Rf is dubnium (Db), followed by seaborgium (Sg), bohrium (Bh), hassium (Hs), meitnerium (Mt), darmstadtium (Ds), roentgenium (Rg), copernicium (Cn), nihonium (Nh), flerovium (Fl), moscovium (Mc), livermorium (Lv), tennessine (Ts), and the final one in the periodic table – oganesson (Og). 
  2. Ernest Rutherford, 1st Baron Rutherford of Nelson, is known as the father of nuclear chemistry and nuclear physics. This great scientist discovered some of the basic concepts in chemistry, such as the nuclear half-lives, atomic nucleus, the proton, the alpha particle, and the beta particle. Rutherford also worked on radioactivity, the effects of X-rays on gases, as well as on the deliberate transformation of one element into another. 
  3. After its discovery in 1964, rutherfordium was resynthesized in 1969. 
  4. The American discovery of element 104 was independently confirmed in 1973. On the other hand, the work of the Dubna team of researchers was subjected to harsh criticism for altering and amending their findings in order to make their research data more credible.
  5. Since rutherfordium is a highly reactive radioactive substance, it could be successfully used in the production of nuclear power, as well as in radiology.