Nobelium: synthetic, radioactive, and vanishingly rare — you won’t find it in nature. Atomic number 102, symbol No, with a half-life measured in minutes. First spotted in 1958, it’s never appeared in bulk, never turned up anywhere outside a lab.
Where it sits in the grand scheme of things
That whole row is the actinides, and every element past uranium (92) is synthetic—no exceptions. Nobelium sits at the tail end of the actinide series, right before the synthetic transition metals, like an uninvited guest who wandered into the wrong party. It’s never shown up in Earth’s crust, meteorites, moon rocks, or starlight; what we know comes from particle accelerators and nuclear chem labs.
Key details at a glance
| Property | Value |
|---|---|
| Atomic number | 102 |
| Symbol | No |
| Group / Period / Block | Actinide / 7 / f-block |
| Standard atomic weight (IUPAC 2021) | [259] |
| Most stable known isotope | No-259 |
| Half-life of No-259 | 58 minutes |
| Production method | Cyclotron: curium-248 + carbon-12 → nobelium-254 + neutrons |
| Discoverers & date | Ghiorso, Sikkeland, Walton & Seaborg; April 1958 |
| Crystal structure observed? | No—still hasn’t been seen in solid form as of 2026 |
| Natural occurrence | None detected anywhere in the universe |
How you actually make a few atoms of No
The collision fuses nuclei, spits out a few neutrons, and occasionally leaves behind a single nobelium-254 or -259 atom. The whole process yields about one atom per hour, and it decays within minutes. The IAEA Nuclear Data Services keeps tabs on the handful of atoms produced since 1958; by 2026 the global count is still in the low thousands.
Why Alfred Nobel’s name ended up on something you can’t touch
Back in 1956, a team at the Nobel Institute in Stockholm led by Torbjørn Sikkeland claimed they’d spotted it first by bombarding curium with carbon ions. A few months later, Albert Ghiorso’s group at Berkeley repeated the experiment, gathered cleaner data, and published definitive proof in April 1958. The International Union of Pure and Applied Chemistry officially credited Berkeley in 1997, so the element carries Nobel’s name. The twist? The Nobel Foundation funded a lot of mid-century chemistry research, which is why his legacy ended up on the periodic table. Funny enough, the same Berkeley lab also cooked up berkelium and californium, so the “-ium” suffix in that neighborhood feels like a science frat’s handiwork.
Should you worry about nobelium?
Even if you somehow snagged a microgram, its radioactivity (alpha decay) would be the main risk, but the quantities produced are smaller than a speck of dust. The International Atomic Energy Agency lists it under “elements of radiological concern,” but that’s purely precautionary—like slapping a “flammable” label on a single match. No occupational exposure limits exist because nobody’s ever had a job handling the stuff.
Want to see where it’s made? Head to the Lawrence Berkeley National Laboratory in California. Their 88-inch cyclotron still fires up now and then for superheavy-element research. Public tours aren’t an option, but the visitor center has a periodic table with a blinking “No” that reads “Ask us how we make it!”—a cheesy but honest reminder that this element is pure human ingenuity, not a chunk of Earth.
