102NoNobelium[259]
Actinide

Nobelium (No)

“Mis-named from birth: Sweden’s Nobel Institute claimed element 102 in 1957 — the claim failed, but the name nobelium stuck forever.”

Atomic number102
Atomic mass[259]
Groupf-block
Period7
BlockF-block
PhaseSolid
Electron structure

How its electrons are arranged

No
[Rn] 5f14 7s2
Shell 1
2e⁻
Shell 2
8e⁻
Shell 3
18e⁻
Shell 4
32e⁻
Shell 5
32e⁻
Shell 6
8e⁻
Shell 7
2e⁻

Computed from the aufbau principle, with known real-world exceptions applied automatically.

Study

The notes

About the element

Characteristics

  • A synthetic, fiercely radioactive actinide; its most stable isotope No-259 decays with a half-life of only about 58 minutes.
  • Chemically rebellious for an actinide: in aqueous solution it prefers the +2 state (No²⁺), made possible by its completed 5f¹⁴ shell.
  • Its isotopes are produced just a few atoms at a time in heavy-ion accelerators, and every sample disappears within hours.
  • Sits in Period 7’s f-block with the other late actinides, closing in on the end of the actinide series.
Appearance

Nobelium has never been collected into anything you could see — it is born a few atoms at a time inside accelerators and is gone within hours. It is presumed to be a silvery, ferociously radioactive actinide metal, though its actual look remains unverified.

Real world

Where you meet it

✦ Uses

  • Testing nuclear decay-scheme models — the alpha chains of isotopes such as No-259 help map energy levels in the heaviest nuclei.
  • Benchmarking actinide separation chemistry: nobelium’s rare +2 behaviour is a key test case for ion-exchange methods.
  • Accelerator technique development — its known synthesis reactions are used to improve heavy-ion beam yields for element hunting.

◍ Everyday examples

  • Every December’s Nobel Prize announcements echo this element’s name — honours paid from Alfred Nobel’s fortune, the man element 102 remembers.
  • The nobelium naming mix-up is a textbook lesson in why IUPAC demands independent confirmation before a discovery counts.
Story

History & name

In 1957 a team at the Nobel Institute for Physics in Stockholm claimed element 102 after bombarding curium-244 with carbon-13 ions, naming it nobelium after Alfred Nobel, the Swedish inventor of dynamite. The claim could not be repeated, and Berkeley’s 1958 attempt also misread its products. The first convincing synthesis came in 1966 at the Joint Institute for Nuclear Research in Dubna, where researchers fired neon-22 ions at uranium-238; international review in the 1990s finally credited the Dubna work — yet the beautiful, wrongly-born name nobelium was kept.

Name originHonours Alfred Nobel, Swedish inventor of dynamite and founder of the Nobel Prizes.