Scientists Can Finally Study Einsteinium 69 Years After Its Discovery
The 20th century was notable for numerous reasons, not least of which that humanity split the atom. In the remnants of atomic explosions, scientists found never-before-seen elements like einsteinium. Now, almost 70 years after its discovery, scientists have collected enough einsteinium to conduct some basic analysis.
Scientists understood that something should exist on the periodic table where einsteinium sits (atomic number 99), but the material had never been identified before 1952, which is when the United States set off the “Ivy Mike” thermonuclear bomb in the Marshall Islands (see above). However, einsteinium is extremely unstable, and it decayed before we could learn much about it. That’s been the case for the intervening 69 years, until now.
We no longer have to make einsteinium with hydrogen bombs, thank goodness. Scientists have a regular, if meager, source of einsteinium from Oak Ridge National Laboratory’s High Flux Isotope Reactor. This device is used to produce heavy elements like californium (atomic number 98). Scientists make californium because it’s an excellent source of neutrons, but the process also yields some einsteinium. Usually, einsteinium is mixed up with other materials and decays rapidly into berkelium and then into californium.
Researchers from Lawrence Berkeley National Laboratory managed to isolate a tiny sample of pure einsteinium, a mere 200 nanograms. Previously, 1,000 nanograms was considered the smallest sample suitable for analysis, but the team prepared their einsteinium for testing and completed an X-ray absorption spectroscopy series. The sample showed a blueshift in the emitted light, meaning the wavelength was shortened. They expected a redshift; longer wavelengths. This suggests einsteinium’s bond distances are a bit shorter than predicted based on nearby elements on the periodic table.
So that’s potentially fascinating science! But the coronavirus pandemic ruined the experiment as it has so many other things in the past year. The team was unable to complete X-ray diffraction testing that would have told us more about the electron and molecular bond structures of einsteinium before the lab was closed. When the team was again able to access their experiment, too much of the sample had decayed into californium — einsteinium decays at a rate of about 3.3 percent each day. Therefore, the contaminated sample was no longer suitable for testing.
The good news is more einsteinium will be available from the reactor every few months. This first step will pave the way for future research on this mysterious element.