Making more than just trace amounts of it means bombarding lighter elements with neutrons for a prolonged period of time – a process that can only be done at one place in the world, the high flux isotope reactor at Oak Ridge National Laboratory in Tennessee, US.

As it doesn’t occur on Earth naturally, little is known about its chemistry beyond the fact that it forms a few halide and oxide salts. The organic ligand 3,4,3-LI(1,2-HOPO) forms an Es(III) coordination complex, enabling structural and spectroscopic studiesĭiscovered in the debris after the detonation of the first hydrogen bomb in 1952, einsteinium is a highly radioactive actinide. Source: © Korey P Carter et al/Springer Nature Limited 2021