Today, elements are no longer discovered by chemists working in a laboratory but are synthesised by physicists over the course of billions of collisions, using high-level software to identify the precise moment when a new element is created. These new elements are mostly discovered in a handful of universities, such as Dubna in Russia and Berkeley in California.
Particle accelerators are split into two broad categories: linear particle accelerators and cyclic particle accelerators. In both types, the accelerator consists of a tube that has carefully spaced positive and negative regions. These regions oscillate from positive to negative as a charged particle moves through, but such that regardless of where the particle is, the electrostatic force on it is always in the same direction.
Linear particle accelerators (linacs) have the advantage of not producing synchrotron radiation when operating, which is radiation given off by charged particles when accelerated perpendicular to their direction of motion, such as in a cyclic particle accelerator. This means that linear particle accelerators can accelerate electrons to high speeds for much less energy. However, they require much more material to build than cyclic particle accelerators, especially synchrotrons, as in these particle accelerators, the particles are accelerated in a loop of tubing, drastically reducing the length needed.
The primary means by which new elements are synthesised is when a lighter ion is accelerated to a very high speed, before being directed at a target made out of a much heavier element. Some of the ions fuse with the nuclei, hopefully creating a new element, which then decays. Very advanced particle detectors then register the decay as unusual, compared to the other collisions registered, and try to figure out the identity of the particle which decayed.
For example, oganesson (element 118) was discovered at the Joint Institute for Nuclear Research in Dubna by bombarding a target of californium-249 with calcium-48 ions to produce oganesson-294. Detecting the presence of oganesson is particularly hard, as it decays with a half-life of 0.9 milliseconds, meaning that precise detecting equipment is needed.
Another problem faced when trying to find a new element is the half-life of the target. This is not a problem when californium-249 is used, as it has a half-life of 351 years. However, other isotopes, such as berkelium-249, are both more costly to produce, and have a shorter half-life (330 days), meaning that after the sample is obtained, it must be used within six months. This was particularly problematic when concerning the synthesis of tennessine (element 117), as the berkelium-249 had to be transported through Russian customs, and was therefore held up for a significant period of time. Luckily, they were allowed through before the target became unusable, saving the University of Livermore several million dollars in recreating a berkelium target.
After the discovery has been validated to the point of certainty, the process of naming the elements begins. This process is regulated by the International Union of Pure and Applied Chemistry, which has laid out specific guidelines for naming elements. After their result is verified, the team of scientists responsible for the discovery has six months to come up with a name and symbol for the element. Customarily, the name will either be in honour of a person (e.g. Rutherfordium) or a place (e.g. Hassium). If the institute fails to decide on a suitable name within 6 months, then the IUPAC will decide themselves. If two institutes collaborate with the discovery of an element, then they have 6 months to decide on a name and symbol, with the IUPAC reserving the right to decide on a name if the two sides cannot agree between them. In such a case, the IUPAC normally tries to name the element using one of the suggested names.
Naming controversies were most common during the Cold War when American and Soviet physicists both claimed to have independently discovered most of the elements between 103 and 109, and therefore gave them names independently in what became known as the transfermium wars. These disputes were dragged out until the end of the Cold War, and even after that for a time American and Russian scientists used different names for the same elements.
These names were resolved in a series of compromises between 1992 and 1997, where element names were standardised. Since then, element naming has generally been a less contentious subject, partially due to decreased tensions between the US and Russia.
Scientists are particularly excited to discover element 121. This is because, according to the Aufbau principle, element 121, provisionally called unbiunium, should be the first element to have an electron occupying a g subshell (5g to be precise). However, due to radial collapse, this may not be the case. The Aufbau principle predicts that lanthanum will have an electron configuration of [Xe] 4f1 6s2, but it actually has a configuration of [Xe] 5d1 6s2, choosing not to fill in the 4f-subshell. Extrapolating from this, it is possible that element 121 may not actually have an electron in the 5g subshell, and the first element with an electron in that type of subshell will actually be later, around element 125. Therefore, discovering element 121 will actually be a very useful and deserving recipient of funding, despite some criticism that money is being wasted on synthesising new elements, with no real purpose.
In the future, new elements may even be stable enough to be observed before they decay, or possibly stable enough to have practical applications (no element past 95 (americium) has a widespread commercial use). This is predicted by the theory of the "island of stability". As a result, discovering new elements may soon be profitable, and have a greater purpose than mere scientific curiosity.
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