Picture this: an element named after the very person who invented the table it sits in. Mendelevium is a tribute to Dmitri Mendeleev, the creator of the periodic system. It is fitting that element 101 carries the name of the scientist who predicted unknown elements long before anyone discovered them.
Mendelevium was created in 1955 by bombarding einsteinium with alpha particles. For the first time in history, a new element was identified from just 17 atoms. It was a genuine triumph of science. Today mendelevium exists only in laboratories and decays within weeks.
Mendelevium is one of the rarest elements on the planet. Its most stable isotope, Md-258, survives for just 51 days. In the entire history of science, no more than billionths of a gram have ever been produced. Studying mendelevium is extraordinarily difficult — you have to work with individual atoms. Yet these very experiments help reveal where the actinides end and the unknown chemistry of superheavy elements begins.
Mendelevium is extremely radioactive. It emits intense alpha particles and gamma rays. In practice, scientists work with it atom by atom, so the real radiation hazard is minimal. But in theory, if it entered the body, it would be extremely toxic. Only a handful of laboratories worldwide have access to mendelevium.
Mendelevium is the only element named after the creator of the periodic table. Dmitri Mendeleev predicted the existence of unknown elements back in 1869.
The first element ever identified one atom at a time. Scientists at Berkeley produced only 17 atoms — and that was enough to confirm the discovery.
At the height of the Cold War, American scientists named an element after a Russian scientist. It was a rare gesture of scientific respect between rival nations.
The longest-lived isotope, Md-258, decays in 51 days. Any sample of mendelevium disappears in less than two months.
| Isotope | Mass (u) | Abundance | Half-life | Decay |
|---|---|---|---|---|
258Md☢ | 258.098431 | synthetic | 51.5 days | α |
260Md☢ | 260.103650 | synthetic | 27.8 days | α/SF |
Cyclotron bombardment of einsteinium