Actinides
Nobelium
A synthetic actinide made only a few atoms at a time.
Atomic #102Mass[259]Blockf-blockPeriod7Group—
No102 · [259]
3D Atom Explorer
Inside the Nobelium atom
Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Nobelium atom step by step.
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Electron configuration
[Rn] 5f14 7s2
A neutral Nobelium atom has 102 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.
Shell distribution
Shell 12 e⁻Shell 28 e⁻Shell 318 e⁻Shell 432 e⁻Shell 532 e⁻Shell 68 e⁻Shell 72 e⁻
Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.
Properties
Physical & atomic properties
- State (room temp)
- Unknown
- Melting point
- 1100 K (827 °C)
- Boiling point
- —
- Density
- —
- Electronegativity
- 1.3 Pauling
- Atomic radius
- —
- 1st ionization energy
- 642 kJ/mol
- Category
- Actinides
History
Discovery & naming
- Discovered
- 1966
- Discovered by
- Dubna and Berkeley teams
- Origin of name
- Chemist and philanthropist Alfred Nobel.
Notable uses
Scientific research only.
Cosmic origin
Where Nobelium comes from
Human synthesis
Synthetic, produced an atom at a time by bombarding actinide targets with ions.
Simplified origin map — many elements form through more than one astrophysical pathway.
Summary
- Atomic number
- 102
- Atomic mass
- [259]
- Category
- Actinides
- Group · Period
- — · 7
- Block
- f-block
- Shells
- 2 · 8 · 18 · 32 · 32 · 8 · 2