It has been almost 90 years since the first synthetic element was artificially created in a lab. That was technetium, discovered in 1937 by Carlo Perrier and Emilio Segrè. The next synthetic element was plutonium, created in 1940. Later on, plutonium would find its application in the creation of the atomic bomb and nuclear reactors.
Although synthetic elements are generally produced in a lab, some of them are naturally occurring but only in trace amounts, so it would be more practical to just synthesize them. The first entirely synthetic element was curium, discovered in 1944 by chemists Glenn T. Seaborg, Ralph A. James, and Albert Ghiorso.
Since curium's synthesis, 23 other synthetic elements have been produced over the course of 60 years. The process by which these synthetic elements are created in the lab is nuclear fusion, whereby one forces two smaller elements' nuclei to collide with each other in order to add protons to the newly formed nucleus of a larger element.
In this process, researchers often employ calcium-48 in particle accelerators to synthesize new nuclei due to its stability and the unusual richness of neutrons in its nucleus, containing 20 protos and 28 neutrons. This is why it has been used to create the five heaviest elements in the periodic table so far, from flerovium to oganesson. However, it's quite tricky when it comes to producing element 120 because it simply does not have enough protons.
Creating heavier elements beyond element 118 would require a beam with more protons. And that's where scientists at Berkeley Lab may have found a small opening for a breakthrough in the quest to create element 120.
Element 120, formally called unbinilium or Ubn, is being considered as a theoretical "island of stability" since models suggest that with the nuclear composition of this element, it will be relatively long-lived, giving scientists an opportunity to study it and perhaps, other superheavy elements, in more detail. Once element 120 is successfully created in a lab, then, it will be the first element to occupy the eighth row of the periodic table, thus opening a new horizon for nuclear physics and materials science.
For now, scientists are still trying to find the best way to create it. And Berkeley Lab, which has already discovered 16 elements, may be on its way to unlocking element 120. So, instead of using calcium-48, they tried a titanium-50 beam to successfully produce element 116, livermorium. This breakthrough may be the avenue needed.
In theory, the proposed method of making element 120 is to collide titanium-50, which has 22 protons, with californium-249, which has 98 protons, thereby resulting in element 120. Although they were successful in this attempt, they say it may still take years before we can finally see element 120 brought to fruition.
There are still many uncertainties about titanium-50. One of the main concerns with titanium-50 is its instability, which lowers the chance of having successful nuclear fusions. Furthermore, the researchers found it difficult to work with titanium-50 because it has a higher melting point, double that of calcium-48. However, for now, it is the most viable option.
(Image credit: Szczureq/Wikimedia Commons; Jenny Nuss/Berkeley Lab)