An element born in the fire of the first hydrogen bomb. In 1952, scientists found an unknown isotope in the radioactive debris of the "Ivy Mike" test. Uranium had absorbed 15 neutrons in microseconds of the blast and transformed into something new. That is how humanity accidentally discovered einsteinium — element 99.
Named after Albert Einstein, this element remains one of the least studied. Less than one gram has been produced in all of history. It is so rare that scientists have never seen it in a quantity visible to the naked eye. Only in 2021 did researchers first study its chemical properties — using just 200 nanograms.
Einsteinium is a radioactive metal from the actinide group, the seventh transuranic element. Its isotopes decay rapidly: the longest-lived Es-252 survives only 472 days. Because of this, einsteinium cannot be accumulated in significant quantities — it vanishes faster than it can be produced.
The discovery of einsteinium was classified until 1955 due to its connection with nuclear testing. Today it is obtained in high-flux reactors, but only in microgram quantities. The key scientific achievement of 2021 was the first measurement of einsteinium's bond length, which upended our understanding of heavy actinide chemistry.
Einsteinium is extremely radioactive and dangerous. It emits intense alpha particles, beta rays, and gamma radiation. Some isotopes undergo spontaneous fission, releasing neutrons. Due to radioactive self-heating, einsteinium destroys its own crystal structure over time. Work is only possible in sealed hot cells with fully remote manipulation.
Einsteinium was born in the blast of the first hydrogen bomb, "Ivy Mike," in 1952. Uranium-238 captured 15 neutrons in microseconds — and created a brand new element.
The discovery was kept secret for three years. The US government classified einsteinium because its existence revealed details about hydrogen bomb design.
Named after Albert Einstein. The name was announced in 1955 — just months after the great physicist's death.
In 2021, scientists first studied einsteinium's chemistry using only 200 nanograms — that's less than the weight of a single human cell.
Einsteinium is so radioactive it heats itself. If you could collect a visible amount, it would glow from its own radiation.
| Isotope | Mass (u) | Abundance | Half-life | Decay |
|---|---|---|---|---|
252Es☢ | 252.082980 | synthetic | 471.7 days | α |
253Es☢ | 253.084820 | synthetic | 20.47 days | α |
254Es☢ | 254.088022 | synthetic | 275.7 days | α |
First hydrogen bomb test debris