Nobelium is a radioactive research element made through nuclear reactions, including bombardment of curium with carbon nuclei. Its discovery history involved competing experimental claims and later assessment. It therefore offers an example of why evidence quality and reproducibility matter when identifying a new element.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
What turns a nobelium laser response into an atomic-state test?
Nobelium atoms in laser-spectroscopy experiments
FOLLOW THIS RELATIONSHIP
Define the proposed transition
An atomic-state calculation predicts relationships among electronic energies. The experiment needs a specified transition or response against which that prediction can be evaluated.
Explore the model (optional)
NoFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Optional: check your understanding
USE THE EXPLANATION
Which conclusion is directly supported by an assigned atomic transition?
Atomic identity, reference properties and structure models
INTERACTIVE 3D102 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[Rn] 5f14 7s2. Grouping electrons by principal shell connects the neutral-atom configuration to periodic-table patterns.
What this representation means
A three-dimensional counting diagram. Dots are count markers, not measured electron positions; spherical placement and spacing are arbitrary. There are no electron trajectories here. Orbitals describe quantum states.
Nobelium’s history includes claims from Stockholm, Berkeley and Dubna that did not all withstand later scrutiny. The 1957 Swedish claim supplied a name honoring Alfred Nobel, but reliable identification came from the Dubna work reported in the 1960s. The familiar name survived reassessment of discovery credit. This case separates three questions often collapsed into one: who reported a signal, whose evidence established the element, and which name the community retained.
1957
Early claim
A Stockholm team reports a discovery later found unreliable.
1966
Reliable identification
Dubna work establishes element 102 in the accepted discovery history.
Nobelium is made in nuclear-reaction experiments, not recovered from natural . Research uses small numbers of radioactive atoms or . Their production is coupled to rapid observation, so the element’s existence in a laboratory does not imply a stock of metal available for conventional physical testing or commercial applications.
Nobelium’s filled 5f shell helps explain the unusual stability of its +2 state compared with many actinides. Researchers can also study neutral atoms through laser spectroscopy. These are distinct electronic situations: removing to make an ion is a chemical change, while adding creates a different .
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
Not recorded
293.15 K, 101.325 kPa
Melting point
Not recorded
at standard pressure unless noted
Boiling point
Not recorded
101.325 kPa
Density
Not recorded
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity in Pauling
1.3 Pauling
Pauling scale
First ionization energy in kJ/mol
642 kJ/mol
gas-phase neutral atom, ground state
Covalent radius
Not recorded
single-bond covalent radius
Common oxidation states
+2
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust
Not recorded
upper continental crust, mass fraction
Has stable isotopes
Noderived
Discovery year in CE
1966 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 7
No 1.3 Pauling · Nobelium
Electronegativity across period 7. Exact values.
Ra
0.9
Ac
1.1
Th
1.3
Pa
1.5
U
1.38
Np
1.36
Pu
1.28
Am
1.13
Cm
1.28
Bk
1.3
Cf
1.3
Es
1.3
Fm
1.3
Md
1.3
No
1.3
Lr
1.3
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
