The history of chemistry has not once seen representations of the periodic system that have not received proper attention or recognition. The present paper is dedicated to a nearly unknown version of the periodic table published on the occasion of the centenary celebration of Mendeleev’s birth (1934) by V. Romanoff. His periodic table visually merges Werner’s and Janet’s periodic tables and it is essentially the spiral periodic system on a plane. In his 1934 paper, Romanoff was the first one to introduce the idea of the actinide series, a decade before Glenn T. Seaborg, the renowned creator of the actinide concept. As a consequence, another most outstanding thing about Romanoff’s paper occurs towards its very end: he essentially predicted the discovery of elements #106, #111 and #118. He theorized that, had uranium not been the “creative limit”, we would have met element #106, a “legal” member of group 6, element #111, a precious metal, “super-gold” and element #118, a noble gas. In 2019, we take it for granted that elements #106, #111 and #118 indeed exist and they are best known as seaborgium, roentgenium and oganesson. It is fair to say that Romanoff’s success with the prediction of correct placement and chemical properties of seaborgium, roentgenium and oganesson was only made possible due to the introduction of an early version of the actinide series that only had four elements at that time. Sadly, while Professor Romanoff was imprisoned (1938–1943), two new elements, neptunium (element #93) and plutonium (element #94) were discovered. While Professor Romanoff was in exile in Ufa (1943–1953), six further elements were added to the periodic table: americium (element #95), curium (element #96), berkelium (element #97), californium (element #98), einsteinium (element #99) and fermium (element #100). The next year after his death, in 1955, mendelevium (element #101), was discovered. Romanoff’s version of the periodic table is an unparalleled precursor to the contemporary periodic table, and is an example of extraordinary anticipation of the discovery of new chemical elements.
The history of chemistry has not once seen representations of the periodic system that have not received proper attention or recognition. These stories began even before Mendeleev’s groundbreaking discovery in 1869 . Arguably, the two most underestimated representations of the periodic system were published by Werner  and Janet .
However, the present paper is dedicated to a nearly unknown version of the periodic table published on the occasion of the centenary celebration of Mendeleev’s birth (1934) by V. Romanoff.
Romanoff’s short biography
In 1934, in a French journal “Revue scientifique”, V. Romanoff published a paper titled “Le système périodique de Mendéléef par représentation graphique” . Romanoff’s periodic table can be also found in van Spronsen’s famous “The periodic system of chemical elements: A history of the first 100 years”  (pp. 155–157).
Viatscheslaw Iljitsch Romanoff (1880–1954) was a Russian physicist born in Moscow (http://letopis.msu.ru/peoples/1019). He lived most of his life in Moscow (http://arch.iofe.center/showObject/452631248). Romanoff was a student of Nikolay Yegorovich Zhukovsky (http://www.r-ff.com/history/historyfiles/VIRomanoff.html). A photo of Viatscheslaw Romanoff in his student years is given in Fig. 1.
In 1902 he graduated from The Faculty of Physics and Mathematics of Imperial Moscow University. From 1902 to 1911 he worked in Pyotr Nikolaevich Lebedev’s laboratory of Imperial Moscow University as his assistant.
Romanoff started as a professor at Moscow State University in 1919. He lectured on “General Physics”. In 1935 he was awarded the degree of Doctor of Sciences (D.Sc.) in Physical and Mathematical Sciences on the basis of published works (over 30 papers and several patents). Figure 2– shows a photo of Viatscheslaw Iljitsch in the physical laboratory of Moscow University.
Romanoff worked at Moscow State University from 1917 to 1938.
Romanoff’s periodic table
His neat version of the periodic table is given in Fig. 3. One does not need to be exceptionally familiar with the world of the periodic system to notice that Romanoff ’s periodic table visually merges Werner’s  and Janet’s  periodic tables.
In his 2006’s book Henry A. Bent (p. 21) classified Romanoff’s table as an “sfdps” one for having an entire block in two places . An sfdps table would result in from merging what we know today as a 32-column periodic table and a left-step periodic table. Hence, an sfdps table is essentially a 34-column periodic table.
However, it is surprising that Romanoff, having depicted a 34-column periodic table (in fact, even a 35-column, if one takes into account scandium, yttrium, lanthanum and actinium on the right), never discusses it as such. What did Romanoff have in mind when he wrote his 1934s paper? He started with paying respect to Mendeleev’s great discovery and his brilliant intuition, stating, however, that Mendeleev’s table only holds up as a first approximation of periodicity. He claimed that a modern periodic table had to be based on electronic structure of atoms (an advantage Janet’s table is well known for). Next, he introduced his version of the periodic table, comparing it to Mendeleev’s (top of Fig. 3). He argued that a “natural” periodic table should have unequal periods of 2, 8, 8, 18, 18, 32 and 6 elements (the last one would have had 32 elements, too, had any transuranium elements been known). Each period, according to Romanoff, has to occupy its own line, and, as there is “no reason to follow the bad habit and compress the 14 rare-earth metals in the same box”, the periodic table should necessarily be formed of 32 columns. Interestingly, in his approach he addressed the issue which Werner had addressed 29 years prior to that (the need to incorporate the lanthanides into the main body).
To understand the idea behind Romanoff’s unconventional 35-column periodic table, one should look at the diagram at the bottom of Fig. 3. The diagram was created by Romanoff to depict the order for filling the electron subshells, for which he chose a spiral. To allow for this spiral, Romanoff had to duplicate the first three columns of the periodic table on its right, thus prolonging the previous periods. This approach resulted it the 35-column periodic table under observation. Meanwhile, this “addition” of three columns on the right of the periodic table essentially makes the diagram on the bottom of Fig. 3 a left-step periodic table, where each element has a different vertical position so that an uninterrupted spiral can be drawn.
It is fair to say that Romanoff created the modern version of what we know today as the 32-column periodic table. Despite the fact that Werner essentially anticipated it in 1905, Romanoff was able to devise its correct iteration because he had the knowledge of electronic structure of atoms at his disposal.
Regretfully, Romanoff’s paper has no citations and does not mention any periodic table contributors rather than Mendeleev and Curie. However, it is safe to assume that he was unaware of Werner’s 33-column periodic table published in German in 1905, or else he would not have to reinvent the idea of incorporating the lanthanides into the main body of the table. Likewise, had he been aware of Janet’s left-step periodic table published in 1928, Romanoff would have noticed that Janet’s version was secretly hidden in his own.
As a result, Romanoff’s did not take advantage of the fact that he unintentionally merged maybe the two most well-known today “alternative” versions of the periodic table.
In 2017, Romanoff’s periodic table has been unintentionally recreated in Journal of Chemical Education in an attempt to describe the transition from a left-step periodic table to a 32-column periodic table in 2D . Both versions are well interconnected through a spiral representation, while a 2D-approach to explanation of said transition led to the recreation of Romanoff’s periodic table.
The spiral periodic system can be considered the fundamental one or the primary one as it can be simply transformed in many other representations, including a 32-column periodic table and a left-step periodic table by cutting between different blocks of chemical elements . Romanoff’s periodic table is essentially the spiral periodic system on a plane. Hence, it bears a significant fundamental and educational relevance, providing the ability to witness both “chemical periods” and “orbital periods” of chemical elements.
V. Romanoff has shown through his approach that the lanthanide series (or the “rare earth series”, as he called it) is a logical necessity rather than an “enigma” of the periodic table as it had been previously known. However, his train of thought was not limited by only the lanthanide series. He stated that, had there been similar phenomena in the periodic system elsewhere, especially in the seventh period, it had to be sought.
Romanoff then points out at the resemblance between the existing members of the seventh period and the beginning of the sixth period and reiterates his statement that the rare-earth metals do not have to be forced into one box in order for uranium to be placed under tungsten (an approach that was usually used). Romanoff comments on the placement of thorium and uranium extensively. He emphasizes the fact that, although their “legal” placement in the periodic is that of under the lanthanides, their kinship with elements of the groups 4 and 6, where Mendeleev had to put them, is also explainable. Romanoff comments that thorium’s and uranium’s electrons are able to pass from the f-subshell to the d-subshell, thus providing for a maximum number of their active electrons. As one can see, here Romanoff relies on chemical properties of elements to explain their placement in the periodic table. It is also clear that Romanoff touches upon the phenomena of the anomalous electron configurations, although he does not call them as such.
Hence, in this 1934 paper, Romanoff in fact was the first one to introduce the idea of the actinide series, a decade before Glenn T. Seaborg, the renowned creator of the actinide concept. David M. Seaborg, the son of Glenn T. Seaborg, states in his recent paper  that his father conceived the actinide concept in the summer of 1944. The concept later went on to be published by G. T. Seaborg in 1946 . Glenn Seaborg, the scientist who added ten elements to the periodic table, was most probably unaware of this Romanoff’s paper.
As a consequence, another outstanding thing about Romanoff’s paper occurs towards its very end: he essentially predicted the discovery of elements #106, #111 and #118. He acknowledged the fact that in the world he lived in there were no chemical elements heavier than uranium (element #92).
However, he theorized that, had uranium not been the “creative limit”, we would have met element #106, a “legal” member of group 6, element #111, a precious metal, “super-gold” and element #118, a noble gas. In 2019, we take it for granted that elements #106, #111 and #118 indeed exist and they are best known as seaborgium, roentgenium and oganesson.
It is fair to say that Romanoff’s success with the prediction of correct placement and chemical properties of seaborgium, roentgenium and oganesson was only made possible due to the introduction of an early version of the actinide series that only had four elements at that time.
Viatscheslaw Romanoff was wrongfully arrested on June 9th, 1938 and imprisoned until 1943. From 1943, while in exile in Ufa (Bashkiria), he taught physics at universities. Professor Romanoff had a lot of talented students . He was only able to return to Moscow after the death of Stalin in the summer of 1953 . Viatscheslaw Iljitsch suffered from poor health and died on September 13th, 1954, in Moscow .
Sadly, while Professor Romanoff was imprisoned, two new elements, neptunium (element #93) and plutonium (element #94) were famously discovered which forever changed the landscape of the periodic table. While Professor Romanoff was in in exile in Ufa, six further elements were added to the periodic table: americium (element #95), curium (element #96), berkelium (element #97), californium (element #98), einsteinium (element #99) and fermium (element #100). The next year after his death, in 1955, mendelevium (element #101), was discovered.
Romanoff’s version of the periodic table is an unparalleled precursor to the contemporary periodic table, and is an example of extraordinary anticipation of the discovery of new chemical elements.
Viatscheslaw Iljitsch Romanoff was a remarkable person of numerous talents. He is proudly and with love remembered by his family (Fig. 4).
Viatscheslaw Romanoff’s SCOPUS Author ID: 57190320180.
A collection of invited papers based on presentations at Mendeleev 150: 4th International Conference on the Periodic Table (Mendeleev 150), held at ITMO University in Saint Petersburg, Russian Federation, 26–28 July 2019.
The author warmly acknowledges: Philip J. Stewart for his kind help with finding the original Romanoff’s paper published in “Revue scientifique”. Sarah Hijmans for her great help in Paris libraries which very importantly revealed that V. Romanoff was from USSR rather than France (it happened on June 19th, 2019). Naum Solomonovich Imyanitov for his great help in Saint Petersburg (Library of the Russian Academy of Sciences) and Internet open sources which revealed basic biographical information about V. Romanoff. Also, Naum Solomonovich was the one to tell the author about Romanoff’s periodic table in the first place (it happened on April 12th, 2018). The Romanoff family, namely Ermolay Romanoff, Tatiana Romanoff, Irina Romanoff and Alexander Romanoff for their great, wholehearted and touching help, readiness to assist in all possible ways to bring this story to life, the exclusive materials from their family archive and various biographical details that are only used in the present paper to tell a coherent story of Romanoff’s brilliant creation.
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