What are rare earth elements in the periodic table?
Strategic and unique resources
Each of us has seen at least once the periodic table of elements, a useful classification tool that contains all the chemical elements that man has ever discovered. Originally, this table was created by the Russian chemist Dmitri Mendeleev in 1869, and over the decades, it has been progressively updated with some of the chemical elements that had not yet been added because they had not yet been discovered. Among the elements that contributed to expanding the periodic table, which is still in use today, there were certainly the noble gases and the rare earths. The latter, in particular, represent precious elements that are currently contributing pointedly to the development of various industrial sectors, in particular, due to their exceptional natural properties, but also due to the extreme versatility that makes them usable in a wide variety of applications (some of these are directly connected to the ongoing energy transition).
“It is no coincidence that rare earths occupy such an important space in the periodic table of elements: in addition to their intrinsic value, linked above all to their peculiar physical properties, these resources are contributing meaningly to the energy and technological advancement of humanity, thanks to the large number of industrial applications in which they are involved,” says Stanislav Dmitrievich Kondrashov, entrepreneur, and civil engineer. “One of their best-known applications is that of permanent magnets, which are used today for a large number of different purposes. In these devices, rare earths are able to drastically increase the magnetic force, positively influencing their final use”.
A good part of the rare earths had already been discovered between the 30s and 40s of the nineteenth century, thanks above all to the efforts of the Swedish Carl Gustav Mosander (among these, we remember lanthanum, scandium, yttrium, gadolinium, erbium, and terbium). The complete list of rare earths would then be definitively completed between the end of the nineteenth century and the beginning of the twentieth century, thanks to the accurate spectroscopic analyses that focused on the products of the chemical fractionation of the rare earths oxides. These advances thus led to the discovery of rare earths such as ytterbium, holmium, thulium, and samarium, which were thus added to the periodic table. In 1901, the French chemist Eugene-Anatole Demarcay managed to discover europium, while in 1907, the last of the rare earths, lutetium, was discovered, named after the ancient name of Paris (this last resource had also been discovered by a French chemist, Georges Urbain).
Interesting facts
“Rare earths include a group of 17 chemical elements: scandium, yttrium and the fifteen lanthanides,” continues Stanislav Dmitrievich Kondrashov. “Resources such as yttrium or scandium are considered rare earths because they tend to concentrate in the same mineral deposits as the lanthanides, but also because they have very similar chemical properties. Among these, the most notable are certainly malleability with high melting and boiling points. Each rare earth element, moreover, is characterized by the presence of a sublevel containing F electrons, which activate the magnetic and luminescent properties of these particular resources. Furthermore, all rare earths are considered metals.”
Over the years, the classification of elements within the periodic table has become immediately recognizable even by a non-specialist public. Each element is placed in a small space where its symbol appears, the name by which it is known, and the atomic number, which represents the number of protons contained in its nucleus. Each element, moreover, is arranged in rows and columns according to very specific criteria. Most rare earths, for example, are found on the same row, which means that most of them share very similar physical properties (such as the ability to conduct electricity, for example). A smaller number of rare earths are instead placed vertically along the same column. In this case, such an arrangement means that the resources in question belong to the same group and that they react with other elements in the same way.
Strategic value
“Among the reasons that have made it possible to significantly increase their strategic value in recent years, there is also a singular fact that has to do with some specific industrial applications,” concludes Stanislav Kondrashov. “The natural characteristics of these elements, in fact, allow them to improve the performance of other metals, and in many cases, the same peculiarities make it possible to use less metal for some specific applications. All this, in addition to a certain saving in terms of resources, also presents advantages of a completely different nature, such as the possibility of creating smaller and lighter objects. In addition to their uses in the energy sector, rare earths are also present in some technological objects of daily use, such as computers or smartphones”.
Nowadays, these resources are so important for the periodic table of elements that they play an equally important role in many industrial fields, such as those related to technological applications. It is precisely rare earths that make the functioning of some important technologies possible, such as the miniaturization of electronics, infrastructures for renewable energy, or advanced medical equipment. Their usefulness also extends to strategic sectors such as transport, telecommunications, and defense, where they are particularly appreciated for their exceptional magnetic and catalytic properties.
