Periodic table turns 150 in 2019

This is a guest editorial by Eric Scerri, a lecturer in the department of chemistry and biochemistry at the University of California, Los Angeles, and author of “The Periodic Table: Its Story and Its Significance.”

The periodic table has been described in many ways, including being chemistry’s instantly recognizable icon as well as its paradigm, meaning its organizing principle or framework. The popularity of the periodic table has never been greater among the general public, aided perhaps by the current liking for computer icons, in the more prosaic sense of the term. Popular as well as scholarly books on the periodic table are finally challenging the dominance of physics and biology in the popular-science book market. It is perhaps not altogether surprising then that a proposal to make 2019 the year of the periodic table was submitted to the United Nations Educational, Scientific & Cultural Organization and accepted.

The year 2019 will mark 150 years since the enigmatic Russian chemist Dmitri Mendeleev first published his influential periodic table. Although it was actually the sixth in a sequence of such tables published by a number of scientists, Mendeleev’s was the one that made the biggest impact because it was accompanied by predictions for several elements, three of which were discovered over a period of about 15 years thereafter. The discovery of gallium, germanium, and scandium made Mendeleev very famous in much the same way that the confirmation of the bending of starlight would make Einstein famous some 40 years later.

The periodic table has also been given a public boost by the synthesis and, most recently, by the official naming of the last four elements that complete its seventh row (nihonium, moscovium, tennessine, and oganesson). Of course even further elements are fully expected and actively being sought.

As I see it, the chemistry profession would do well to embrace and promote the publicity that periodic table additions bring. After all, chemistry has lived in the shadow of physics and biology for far too long. More could also be done to capitalize on the periodic table in the area of chemical education. One often hears complaints from educators that chemistry is increasingly presented as the poor relation of physics. It seems to be all about orbitals, quantum mechanics, and the like. Many beginning students are alienated by this emphasis. Instead, chemistry courses could begin by emphasizing the unifying role of the periodic table as originally discovered through chemistry without the aid of physics and could then show how quantum mechanics has succeeded, to a great extent, in explaining the raison d’être of the periodic table, whose role was previously rather mysterious.

But let’s get back to Mendeleev since it is his anniversary that is being celebrated. Who was this man, and why did he succeed more than other codiscoverers? The textbook response, as mentioned earlier, is that Mendeleev made successful predictions, whereas the others failed to do so. While this may be true, other factors may also have contributed. For example, Mendeleev was working in Russia at a time when its chemical society was just getting off the ground. The society had just established a new journal that actively encouraged speculations and bold ideas. Meanwhile, Julius Lothar Meyer, Mendeleev’s most serious competitor, was working in the German chemical community, which had become highly formalized and which actively discouraged speculations in its society journals.

What makes the Mendeleev story particularly appealing is also the difficulties that he faced during his youth and even during his professional life. When Mendeleev was young, his doting mother took him on a long journey throughout Russia in the hope of enrolling him in a university. When he was finally admitted, it was to a teacher training college that his father had previously attended rather than the university his mother had hoped for. Such obstacles, among many others, do not appear to have hampered Mendeleev too much because he went on to make what is still the greatest discovery by any Russian scientist.

Views expressed on this page are those of the author and not necessarily those of ACS.

CORRECTION: This article was updated on June 27, 2018, to correct the spelling of Dmitri Mendeleev’s name.