Einsteinium, the elusive 99th element in the periodic table, was created and recorded, allowing some of its properties to be characterized for the first time.
The so-called ‘synthetic element’, which does not occur naturally on Earth, was first discovered in the debris of the very first hydrogen bomb in 1952.
Very few experiments with einsteinium have been done since then, as it is extremely radioactive and extremely difficult to produce.
However, US researchers have used the very latest technology to create 250 nanograms of the element.
This basic property determines how einsteinium will bond with other atoms and molecules and is key to understanding the types of chemical interactions it can have.
Einsteinium – the elusive 99th element in the periodic table – was created and recorded, allowing for the first time characterization of some of its properties
The so-called ‘synthetic element’, which does not occur naturally on Earth, was first discovered among the debris of the very first hydrogen bomb (photo), code-named ‘Ivy Mike’, in 1952
“Not much is known about einsteinium,” said paper author and heavy element chemist Rebecca Abergel of Lawrence Berkeley National Laboratory in California.
‘It is a remarkable achievement that we were able to work with this small amount of material and do inorganic chemistry.
‘It’s important because the more we understand about it [einsteinium’s] chemical behavior, the more we can apply this concept to the development of new materials or new technologies. ‘
This, she explained, could help not only directly find uses for einsteinium, but also the rest of the actinides – the block of 15 metallic and radioactive elements with atomic numbers between 89 and 103.
At the same time, the new findings can help chemists identify new trends within the elements that make up the periodic table.
In their study, Professor Abergel and colleagues produced their einsteinium sample in the so-called High Flux Isotope Reactor at Oak Ridge National Laboratory in Tennessee, one of the few facilities in the world that can make the element.
The material was created by bombarding curium – another radioactive actinide series element – with neutrons to initiate a long chain of nuclear reactions that ultimately yield the desired einsteinium.
Making meaningful amounts of pure einsteinium, however, is extremely challenging, and the team’s sample was contaminated with a californium.
This prevented them from using X-ray crystallography – the gold standard for obtaining structural information about highly radioactive molecules – on their sample, forcing them to develop new approaches and tools to study their einsteinium.
A second problem arose as a result of COVID-19, the pandemic that forced the team to close their lab before they could complete many of their planned follow-up experiments on the sample.
Although they produced one of the more stable isotopes of einsteinium, it still only had a ‘half-life’ – the time it took half the material to decay into something else – of 276 days, meaning much of their monster had disappeared by then. they have come back.
EINSTEINIUM: THE BASIS
Pictured, a 300 microgram sample of einsteinium, stored in a quartz vial
Einsteinium is a soft, silvery metal element with the symbol ‘Es’ and an atomic number of 99 (that is, the nucleus contains 99 protons).
Like all other elements in the so-called ‘actinide series’ it is extremely radioactive.
When seen in the dark (as shown on the left), samples of einsteinium glow blue.
It was first discovered in the aftermath of the very first hydrogen bomb in 1952.
As a so-called ‘synthetic element’, einsteinium does not occur naturally on Earth. Currently it has not found any application outside of basic scientific research.
It was named in honor of the physicist Albert Einstein.
Very few experiments with einsteinium have been done since then, as it is extremely radioactive and extremely difficult to produce. However, researchers from the US (photo) used the very latest technology to make 250 nanograms of the element
Nonetheless, the researchers were able to subject their einsteinium sample to analysis with luminescence spectroscopy and X-ray absorption spectroscopy – revealing both the bonding distance and some other properties of the element.
“Determining the bond distance may not sound interesting, but it is the first thing you would like to know about how a metal binds to other molecules,” explains Professor Abergel.
Understanding how to arrange the atoms in a molecule with einsteinium can help scientists get a sense of the chemical properties of such molecules and better understand chemical trends in the periodic table.
“By collecting this piece of data, we get a better, broader understanding of how the entire actinide series behaves,” said Professor Abergel.
‘And in that series we have elements or isotopes that are useful for the production of nuclear energy or radiopharmaceuticals.’
The findings, Professor Abergel explained, could help not only directly find uses for einsteinium, but also the rest of the actinides – the block of 15 metals and radioactive elements with atomic numbers between 89 and 103 (shown here in green )
Working with einsteinium also teases the possibility of exploring chemistry beyond the edge of the current periodic table and possibly even the discovery of an entirely new element.
“We’re really starting to understand a little bit better what happens towards the end of the periodic table, and the next thing is that you can also imagine an einsteinium target to discover new elements,” explains Professor Abergel.
Similar to the newest elements discovered in the past 10 years, such as tennessine, which used a berkelium target, if you could isolate enough pure einsteinium to make a target, you could look for other elements . ‘
This, she added, could bring us closer to the theoretical “ island of stability, ” where nuclear physicists predict that isotopes can have half-lives of minutes or days – as opposed to microsecond or less half-lives commonly found with the supermassive elements.
The full findings of the study are published in the journal Nature.