A century ago, a German physicist named Albert Einstein turned the scientific world on its head with his discovery of the photoelectric effect, which turned out to be a particle and a wave. Einstein, who was awarded the Nobel Prize in Physics in 1921 for his work, would later contribute to theories related to nuclear fusion and fission – probably paving the way for the invention and explosion of nuclear weapons, as well as nuclear energy.
And when elements previously unknown to science were discovered 69 years ago in the chemical rubble of a nuclear explosion, it was fitting that scientists found them after the great physicist and added ‘einsteinium’ to the periodic table. has.
Now, 100 years after Einstein won the Nobel Prize, chemists have finally been able to investigate the chemical behavior of this elusive, extremely radioactive element. What they have learned can help scientists further expand our understanding of the periodic table – including elements that still need to be added to it.
Explosive findings
Einsteinium (Es) is the 99th element in the periodic table. It was first discovered in 1952 when a thermonuclear device called “Ivy Mike” exploded on Elugelab Island in the Pacific Ocean (now part of the Marshall Islands). Ivy Mike’s explosion was the first demonstration of a hydrogen bomb. Such an explosion creates four times more energy than nuclear bombs (such as those dropped on Japan in 1945) and four million times more energy than the burning of a similar amount of coal.
It was in the aftermath of Ivy Mike’s explosion, amid the chemical waste, that atomic number 99 was found for the first time. Only about 200 atoms of this element have been detected, which shows how rare it is. It took nine years of careful work before scientists could synthesize element 99 in a laboratory, which they achieved in 1961.
The team of researchers who made the discovery thought of naming the element “pandamonium” as the project team worked behind Ivy Mike under the acronym “PANDA”. But in the end, they decide to honor Albert Einstein.
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Too hot to handle
It is perhaps not surprising that very little is known about einsteinium. An element born in a thermonuclear explosion is incredibly difficult to experiment with because of its extreme radioactivity. Not only is it literally too hot to handle – one gram of einsteinium produces 1,000 watts of energy – it also emits harmful gamma rays, so to work with the element, researchers must wear it at all times.
In addition, einsteinium’s most common form (called Es-253, based on the number of neutrons in the atomic nucleus) has a half-life of only 20 days. This means that einsteinium expires by half after 20 days. After a few months, the small amounts of the element that scientists can work with disappear.
It is therefore no wonder that it took almost 70 years before scientists mastered this element. But now a team from the Lawrence Berkeley National Laboratory and the University of California at Berkeley have managed to determine enough einsteinium to perform basic tests on the element – breaking new ground in experimental chemistry and fundamental science.
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In their paper, the researchers explain how they managed to use only 200 nanograms of Es-254 (a rare form of einsteinium with a half-life of 275.5 days) to perform their experiments. A nanogram is only one billionth of a gram, so these experiments took place on an incredibly small scale.
Einsteinium chemistry
The research team first performed chemistry with einsteinium and succeeded in synthesizing a chemical compound containing the element to investigate how it can interact with other elements in a compound. This was done under the Stanford Synchrotron Radiation Lightsource, which emits high-energy light to chemical compounds to expose their structure. You can consider this method to be similar to how silhouettes are formed – but on an atomic scale.
One major finding was the bonding distances between einsteinium atoms and other atoms around it – such as carbon, oxygen and nitrogen. If you first know the binding distance of einsteinium, you can predict what other combinations of compounds with einsteinium will look like, and this adds new combinations to our current knowledge of chemistry.
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Importantly, the researchers also measure the valence state of einsteinium, which is the charge on the atom. The charge of an atom determines how many other atoms it can bind. This amount is of fundamental importance in chemistry, and determines the shape and size of the building blocks that make up the universe. Einsteinium happens to lie in an ambiguous position between the valence numbers on the periodic table. Determining its valence helps us more to understand what the periodic table should look like.
Einsteinium is currently the heaviest chemical element that can be investigated in this way. It is therefore exciting for chemists that new territory has been broken by this recent article. The challenge facing future chemists is to synthesize heavier elements in similar measurable amounts, and to discover more about the chemicals that make up our world.