ELEMENTLE

Element 102 · Actinide

Nobelium

Period 7

Nobelium is a synthetic chemical element with symbol No and atomic number 102. It is named in honor of Alfred Nobel, the inventor of dynamite and benefactor of science. A radioactive metal, it is the tenth transuranic element and is the penultimate member of the actinide series.

Three reasons Nobelium stands out

  1. 1

    Named after one of the most pretigious awards in the world attributed for contribution to humankind.

  2. 2

    Its discovery was disputed between American and Soviet scientists during the Cold War for several years.

  3. 3

    Its most stable isotope has a half-life of only 58 minutes, making it extremely difficult to study.

A discovery dispute behind a famous name

Nobelium’s history involved competing claims from laboratories in Sweden, the United States, and the Soviet Union. Later work resolved which experiments were convincing, while the name honoring Alfred Nobel survived. Its short-lived atoms reveal chemistry mainly through rapid automated separations.

Nobelium at a glance
Atomic number / protons102
SymbolNo
Family (Elementle)Actinide
Classification (PubChem)Actinide
Period7
GroupLanthanide / actinide series
Atomic mass (u)259.10100
Standard stateBulk state not experimentally established
Electron configuration[Rn]7s2 5f14
Reported oxidation states+3, +2
Electronegativity (Pauling)1.3
Atomic radius (pm)Not available
First ionization energy (eV)6.65
Electron affinity (eV)Not available
Density (g/cm³)Not available
Melting point1100 K (826.85 °C) · estimated
Boiling pointNot available
Discovery (PubChem)1957

Values are reference data, not a specification for every temperature, pressure, or allotrope. Unknown properties are left unavailable. Superheavy-element predictions remain uncertain.

Sources & further reading

PubChem: Nobelium · Nobelium on Wikipedia

The introduction and original editorial story are adapted from Wikipedia contributors via Periodic-Table-JSON. Element descriptions and their adaptations are available under CC BY-SA 3.0. Numerical attributes use the PubChem periodic-table dataset, retrieved September 22, 2026.