Skip to Main Content

About Nobelium

Nobelium Bohr

The discovery of nobelium, a synthetic member of the actinide series, was fraught with controversy and competing claims, and some disagreement persists to this day. Three separate groups have claimed its discovery, and it wasn’t until the 1990s that the IUPAC declared the credit belonged to Russia. It was named nobelium when scientists at the Nobel Institute in Sweden claimed they had discovered it in 1957. That experiment was later discredited and they had to retract their claim, but the name remained. Researchers at UC Berkeley claimed they detected it in 1959, but that work was not verified. Later, work by the Russian Joint Institute for Nuclear Research was credited as the first to correctly identify nobelium.

Only small amounts of nobelium have ever been produced, and its longest-lived isotop has a half-life of only 58 minutes. Much remains unknown about this element and no commercial applications have been developed. However, it has been used to study nuclear fission.

Nobelium Properties

Nobelium (No) atomic and molecular weight, atomic number and elemental symbolNobelium is a Block F, Group 3, Period 7 element. The number of electrons in each of nobelium's shells is 2, 8, 18, 32, 32, 8, 2 and its electron Nobelium Bohr Model configuration is [Rn] 5f14 7s2. The nobelium atom has a Van der Waals radius of 246.pm. In its elemental form, nobelium's CAS number is 10028-14-5. Nobelium is radioactive and its appearance is unknown. The discovery of nobelium was first claimed by researchers in Sweden and then at UC Berkeley in the United States, but these claims could not be verified. The Russian Joint Institute of Nuclear Research was the first team to be able to provide proof of their discovery of the element that was accepted by the international scientific community.

Nobelium was named in honor of Alfred Nobel, the inventor of dynamite.

Symbol: No
Atomic Number: 102
Atomic Weight: 259
Element Category: Actinide
Group, Period, Block: n/a, 7, f
Color: unknown (presumably metallic/ silvery white/ gray)
Other Names: Nobelio
Melting Point: 827°C, 1520.6°F, 1100.15 K
Boiling Point: N/A
Density: N/A
Liquid Density @ Melting Point: N/A
Density @ 20°C: N/A
Density of Solid: N/A
Specific Heat: N/A
Superconductivity Temperature: N/A
Triple Point: N/A
Critical Point: N/A
Heat of Fusion (kJ·mol-1): N/A
Heat of Vaporization (kJ·mol-1): N/A
Heat of Atomization (kJ·mol-1): 108
Thermal Conductivity: N/A
Thermal Expansion: N/A
Electrical Resistivity: N/A
Tensile Strength: N/A
Molar Heat Capacity: N/A
Young's Modulus: N/A
Shear Modulus: N/A
Bulk Modulus: N/A
Poisson Ratio: N/A
Mohs Hardness: N/A
Vickers Hardness: N/A
Brinell Hardness: N/A
Speed of Sound: N/A
Pauling Electronegativity: 1.3
Sanderson Electronegativity: N/A
Allred Rochow Electronegativity: 1.2
Mulliken-Jaffe Electronegativity: N/A
Allen Electronegativity: N/A
Pauling Electropositivity: 2.7
Reflectivity (%): N/A
Refractive Index: N/A
Electrons: 102
Protons: 102
Neutrons: 157
Electron Configuration: [Rn] 5f14 7s2
Atomic Radius: N/A
Atomic Radius,
non-bonded (Å):
2.46
Covalent Radius: N/A
Covalent Radius (Å): 1.76
Van der Waals Radius: 246 pm
Oxidation States: 2, 3
Phase: Solid (predicted)
Crystal Structure: N/A
Magnetic Ordering: N/A
Electron Affinity (kJ·mol-1) Unknown
1st Ionization Energy: 641.6 kJ·mol-1
2nd Ionization Energy: 1254.3 kJ·mol-1
3rd Ionization Energy: 2605.1 kJ·mol-1
CAS Number: 10028-14-5
EC Number: N/A
MDL Number: N/A
Beilstein Number: N/A
SMILES Identifier: [No]
InChI Identifier: InChI=1S/No
InChI Key: ORQBXQOJMQIAOY-UHFFFAOYSA-N
PubChem CID: 24822
ChemSpider ID: 23207
Earth - Total: N/A
Mercury - Total: N/A
Venus - Total: N/A
Earth - Seawater (Oceans), ppb by weight: N/A
Earth - Seawater (Oceans), ppb by atoms: N/A
Earth -  Crust (Crustal Rocks), ppb by weight: N/A
Earth -  Crust (Crustal Rocks), ppb by atoms: N/A
Sun - Total, ppb by weight: N/A
Sun - Total, ppb by atoms: N/A
Stream, ppb by weight: N/A
Stream, ppb by atoms: N/A
Meterorite (Carbonaceous), ppb by weight: N/A
Meterorite (Carbonaceous), ppb by atoms: N/A
Typical Human Body, ppb by weight: N/A
Typical Human Body, ppb by atom: N/A
Universe, ppb by weight: N/A
Universe, ppb by atom: N/A
Discovered By: Joint Institute for Nuclear Research
Discovery Date: 1966
First Isolation: N/A

Nobelium Isotopes

Nobelium is an artificial element. It has no stable isotopes.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
249No 249.087823# 0.8 s a to 245Fm; SF; EC to 249Md N/A N/A 1863.235962 -
250No 250.08756(22)# 5.7(8) µs SF; a to 246Fm; EC to 250Md 0+ N/A 1856.531006 -
251No 251.08894(12)# 0.78(2) s a to 247Fm; SF; EC to 251Md 7/2+# N/A 1863.235962 -
252No 252.088967(10) 2.27(14) s a to 248Fm; SF; EC to 252Md 0+ N/A 1871.302124 -
253No 253.090564(7) 1.62(15) min a to 249Fm; EC to 253Md (9/2-)# N/A 1877.80603 -
254No 254.090956(11) 51(10) s a to 250Fm; EC to 254Md; SF 0+ N/A 1885.597778 -
255No 255.093191(16) 3.1(2) min a to 251Fm; EC to 255Md (1/2+) N/A 1891.54187 -
256No 256.094283(8) 2.91(5) s a to 252Fm; AS 252AS 0+ N/A 1898.641235 -
257No 257.096888(7) 25(2) s a to 253Fm (7/2+) N/A 1904.312134 -
258No 258.09821(11)# 1.2(2) ms a to 254Fm; SF 0+ N/A 1911.128052 -
259No 259.10103(11)# 58(5) min a to 255Fm; EC to 259Md; SF (9/2+)# N/A 1916.56897 -
260No 260.10264(22)# 106(8) ms SF 0+ N/A 1923.139038 -
261No 261.10570(22)# 170 min a to 257Fm 3/2+# N/A 1928.317017 -
262No 262.10746(39)# ~5 ms SF 0+ N/A 1934.732056 -
263No 263.11072(53)# 20# min a to 259Fm N/A N/A N/A -
264No 264.11273(70)# 1# min a to 260Fm 0+ N/A N/A -
Nobelium Elemental Symbol

Recent Research & Development for Nobelium

  • An accurate relativistic universal Gaussian basis set for hydrogen through Nobelium without variational prolapse and to be used with both uniform sphere and Gaussian nucleus models. Haiduke RL, De Macedo LG, Da Silva AB. J Comput Chem. 2005 Jul 15
  • Nobelium: tracer chemistry of the divalent and trivalent ions. Maly J, Sikkeland T, Silva R, Ghiorso A. Science. 1968 Jun 7
  • Oxidation of element 102, nobelium, with flow electrolytic column chromatography on an atom-at-a-time scale. Toyoshima A, Kasamatsu Y, Tsukada K, Asai M, Kitatsuji Y, Ishii Y, Toume H, Nishinaka I, Haba H, Ooe K, Sato W, Shinohara A, Akiyama K, Nagame Y. J Am Chem Soc. 2009 Jul 8
  • Nobelium non-believers. Thornton BF, Burdette SC. Nat Chem. 2014 Jul