This article considers two important traditions concerning the chemical elements. The first is the meaning of the term “element” including the distinctions between element as basic substance, as simple substance and as combined simple substance. In addition to briefly tracing the historical development of these distinctions, I make comments on the recent attempts to clarify the fundamental notion of element as basic substance for which I believe the term “element” is best reserved. This discussion has focused on the writings of (...) Fritz Paneth which are here analyzed from a new perspective. The other tradition concerns the reduction of chemistry to quantum mechanics and an understanding of chemical elements through their microscopic components such as protons, neutrons and electrons. I claim that the use of electronic configurations has still not yet settled the question of the placement of several elements and discuss an alternative criterion based on maximizing triads of elements. I also point out another possible limitation to the reductive approach, namely the failure, up to now, to obtain a derivation of the Madelung rule. Mention is made of some recent similarity studies which could be used to clarify the nature of ‘elements’. Although it has been suggested that the notion of element as basic substance should be considered in terms of fundamental particles like protons and electrons, I resist this move and conclude that the quantum mechanical tradition has not had much impact on the question of what is an element which remains an essentially philosophical issue. (shrink)

Although the periodic system of elements is central to the study of chemistry and has been influential in the development of quantum theory and quantum mechanics, its study has been largely neglected in philosophy of science. The present article is a detailed criticism of one notable exception, an attempt by Hettema and Kuipers to axiomatize the periodic table and to discuss the reduction of chemistry in this context.

The periodic table of the elements is one of the most powerful icons in science: a single document that captures the essence of chemistry in an elegant pattern. Indeed, nothing quite like it exists in biology or physics, or any other branch of science, for that matter. One sees periodic tables everywhere: in industrial labs, workshops, academic labs, and of course, lecture halls. It is sometimes said that chemistry has no deep ideas, unlike physics, which can boast (...) class='Hi'>quantum mechanics and relativity, and biology, which has produced the theory of evolution. This view is mistaken, however, since there are in fact two big ideas in chemistry. They are chemical periodicity and chemical bonding, and they are deeply interconnected. The observation that certain elements prefer to combine with specific kinds of elements prompted early chemists to classify the elements in tables of chemical affinity. Later these tables would lead, somewhat indirectly, to the discovery of the periodic system, perhaps the biggest idea in the whole of chemistry. Indeed, periodic tables arose partly through the attempts by Dimitri Mendeleev and numerous others to make sense of the way in which particular elements enter into chemical bonding. (shrink)

This work utilizes examples from chemical sciences to present fundamentals of dialectics and synergetics. The laws of dialectics remain appropriate at the level of atoms, at the level of molecules, at the level of the reactions, and at the level of ideas. The law of the unity and conflict of opposites is seen, for instance, in the relationships between the ionization energy and electron affinity of atoms, between the forward and back reactions, as well as in the differentiation and integration (...) between the various areas of chemistry. The law of the passage of quantitative changes into qualitative changes describes the transformation properties of the compounds when the number and arrangement of atoms in the molecule undergoes changes. According to this law, the development is accompanied by breaks and jumps. This paper suggests equations for the description of these relationships. The law of the negation of the negation is manifested in the Periodic Law, in the evolution of ideas about the mutual transformation of chemical elements, in the development the concept of triads of elements, etc. Small changes in the conventional Periodic Table on the basis of previously rejected versions allow reflecting secondary and additional periodicity. Synergetics, similarly to dialectics, is dedicated to the studies of general laws of evolution. Synergetics includes highly advanced and specified ideas of dialectics. The cornerstone of synergetics is the principles of self-organization and nonlinearity. Mathematical development of these concepts was substantially facilitated by considering oscillating chemical reactions as an example. These reactions are quite complex and therefore provide adequate models for self-organization. Oscillations may exist only upon execution of specific thermodynamic, mathematical, and chemical conditions. Mechanisms of several oscillatory reactions are briefly reviewed. The construction of novel biomimetic or smart materials based on oscillating reactions is described. (shrink)

Chemistry as the special science of the elements Content Type Journal Article DOI 10.1007/s11016-010-9458-4 Authors Klaus Ruthenberg, Faculty of Science, Coburg University of Applied Sciences, 96406 Coburg, Germany Journal Metascience Online ISSN 1467-9981 Print ISSN 0815-0796.

At the heart of chemistry lies the periodic system of chemical elements. Despite being the cornerstone of modern chemistry, the overall structure of the periodic system has never been fully understood from an atomic physics point of view. Group-theoretical models have been proposed instead, but they suffer from several limitations. Among others, the identification of the correct symmetry group and its decomposition into subgroups has remained a problem to this day. In an effort to deepen our limited understanding (...) of the periodic law, we have extended the traditional Lie algebraic framework to account for the peculiar degeneracy structure of the periodic system. Starting from the four-dimensional hidden symmetry and accidental degeneracy of the hydrogen atom, as first revealed by Fock in 1935, our research has mainly focussed on the way this SO(4) symmetry of the Coulomb potential gets broken in the periodic system as a consequence of the transformation of the hydrogenic (n, l) filling order to the Madelung (n+l, n) order due to electronic repulsions, relativistic effects and spin-orbit couplings. In this PhD dissertation, a new left-step format of the periodic table is first proposed on the basis of the Madelung rule. Following the particle physics tradition, the chemical elements are then considered as various states of some 'atomic matter', which is described by a non-compact spectrum-generating dynamical Lie group. The chemical elements are shown to form a basis for a single infinite-dimensional degeneracy space of the SO(4,2) ⊗ SU(2) group. An explanation for the period doubling is then proposed in terms of a particular symmetry breaking of the SO(4,2) group to the anti de Sitter SO(3,2) group. The Madelung rule is rationalised on the basis of nonlinear Lie algebras which reflect the screening of the Coulomb hole. This opens new perspectives for a symmetry-based understanding of how the periodic law emerges from its quantum mechanical foundations, and holds the future promise of complementing our current phenomenological approach by a direct atomic physics approach. (shrink)

In this essay, we aim to provide an overview of the periodic table’s origins and history, and of the elements which conspired to make it chemistry’s most recognisable icon. We pay attention to Mendeleev’s role in the development of a system for organising the elements and chemical knowledge while facilitating the teaching of chemistry. We look at how the reception of the table in different chemical communities was dependent on the local scientific, cultural and political context, but argue that (...) its eventual universal acceptance is due to its unique ability to accommodate possessed knowledge while enabling novel predictions. Furthermore, we argue that its capacity to unify apparently disconnected phenomena under a simple framework facilitates our understanding of periodicity, making the table an icon of aesthetic value, and an object of philosophical inquiry. Finally, we briefly explore the table’s iconicity throughout its representations in pop art and science fiction. (shrink)

The periodic table represents and organizes all known chemical elements on the basis of their properties. While the importance of this table in chemistry is uncontroversial, the role that it plays in scientific reasoning remains heavily disputed. Many philosophers deny the explanatory role of the table and insist that it is “merely” classificatory (Shapere, in F. Suppe (Ed.) The structure of scientific theories, University of Illinois Press, Illinois, 1977; Scerri in Erkenntnis 47:229–243, 1997). In particular, it has been claimed (...) that the table does not figure in causal explanation because it “does not reveal causal structure” (Woody in Science after the practice turn in the philosophy, history, and social studies of science, Routledge Taylor & Francis Group, New York, 2014). This paper provides an analysis of what it means to say that a scientific figure reveals causal structure and it argues that the modern periodic table does just this. It also clarifies why these “merely” classificatory claims have seemed so compelling–this is because these claims often focus on the earliest periodic tables, which lack the causal structure present in modern versions. (shrink)

Some recent work in mathematical chemistry is discussed. It is claimed that quantum mechanics does not provide a conclusive means of classifying certain elements like hydrogen and helium into their appropriate groups. An alternative approach using atomic number triads is proposed and the validity of this approach is defended in the light of some predictions made via an information theoretic approach that suggests a connection between nuclear structure and electronic structure of atoms.

The recent exchange on the quantum justification of the Periodic System of the Elements in this Journal between Scerri [Foundations of Chemistry 6: 93–116, 2004] and Friedrich [Foundations of Chemistry 6: 117–132, 2004] is supplemented by some methodological comments.

Electronegativity, described by Linus Pauling described as “The power of an atom in a molecule to attract electrons to itself” (Pauling in The nature of the chemical bond, 3rd edn, Cornell University Press, Ithaca, p 88, 1960), is used to predict bond polarity. There are dozens of methods for empirically quantifying electronegativity including: the original thermochemical technique (Pauling in J Am Chem Soc 54:3570–3582, 1932), numerical averaging of the ionisation potential and electron affinity (Mulliken in J Chem Phys 2:782–784, 1934), (...) effective nuclear charge and covalent radius analysis (Sanderson in J Chem Phys 23:2467, 1955) and the averaged successive ionisation energies of an element’s valence electrons (Martynov and Batsanov in Zhurnal Neorganicheskoi Khimii 5:3171–3175, 1980), etc. Indeed, there are such strong correlations between numerous atomic parameters—physical and chemical—that the term “electronegativity” integrates them into a single dimensionless number between 0.78 and 4.00 that can be used to predict/describe/model much of an element’s physical character and chemical behaviour. The design of the common and popular medium form of the periodic table is in large part determined by four quantum numbers and four associated rules. However, adding electronegativity completes the construction so that it displays the multi-parameter periodic law operating in two dimensions, down the groups and across the periods, with minimal ambiguity. (shrink)

The article discusses some of Heinz Post's views on correspondence and whether revolutions occur in science a la Kuhn. For example Post points out that the periodic table of the chemical elements has withstood any revolutions. Specific issues examined include the Paneth-Fajans controversy, the extent to which quantum mechanics provides an explanation for the periodic table and ab initio calculations in quantum chemistry.

The success of a few theories in statistical thermodynamics can be correlated with their selectivity to reality. These are the theories of Boltzmann, Gibbs, end Einstein. The starting point is Carnot’s theory, which defines implicitly the general selection of reality relevant to thermodynamics. The three other theories share this selection, but specify it further in detail. Each of them separates a few main aspects within the scope of the implicit thermodynamic reality. Their success grounds on that selection. Those aspects can (...) be represented by corresponding oppositions. These are: macroscopic – microscopic; elements – states; relational – non-relational; and observable – theoretical. They can be interpreted as axes of independent qualities constituting a common qualitative reference frame shared by those theories. Each of them can be situated in this reference frame occupying a different place. This reference frame can be interpreted as an additional selection of reality within Carnot’s initial selection describable as macroscopic and both observable and theoretical. The deduced reference frame refers implicitly to many scientific theories independent of their subject therefore defining a general and common space or subspace for scientific theories (not for all). The immediate conclusion is: The examples of a few statistical thermodynamic theories demonstrate that the concept of “reality” is changed or generalized, or even exemplified (i.e. “de-generalized”) from a theory to another. Still a few more general suggestions referring the scientific realism debate can be added: One can admit that reality in scientific theories is some partially shared common qualitative space or subspace describable by relevant oppositions and rather independent of their subject quite different in general. Many or maybe all theories can be situated in that space of reality, which should develop adding new dimensions in it for still newer and newer theories. Its division of independent subspaces can represent the many-realities conception. The subject of a theory determines some relevant subspace of reality. This represents a selection within reality, relevant to the theory in question. The success of that theory correlates essentially with the selection within reality, relevant to its subject. (shrink)

Symmetry is at the heart of our understanding of matter. This book tells the fascinating story of the constituents of matter from a common symmetry perspective. The standard model of elementary particles and the periodic table of chemical elements have the common goal to bring order in the bewildering chaos of the constituents of matter. Their success relies on the presence of fundamental symmetries in their core. -/- The purpose of Shattered Symmetry is to share the admiration for the (...) power and the beauty of these symmetries. The reader is taken on a journey from the basic geometric symmetry group of a circle to the sublime dynamic symmetries that govern the motions of the particles. Along the way the theory of symmetry groups is gradually introduced with special emphasis on its use as a classification tool and its graphical representations. This is applied to the unitary symmetry of the eightfold way of quarks, and to the four-dimensional symmetry of the hydrogen atom. The final challenge is to open up the structure of Mendeleev's table which goes beyond the symmetry of the hydrogen atom. Breaking this symmetry to accommodate the multi-electron atoms requires us to leave the common ground of linear algebras and explore the potential of non-linearity. (shrink)

The periodic table is one of the best-known systems of classification in science. Because of the information it contains, it raises explanation-seeking questions. Quantum mechanical models of the behaviour of electrons may be seen as providing explanations in response to these questions. In this paper we first address the question ‘Do quantum mechanical models of atoms provide legitimate explanations?’ Because our answer is positive, our next question is ‘Are the explanations provided by quantum mechanical models of (...) atoms mechanistic explanations?’. This question is motivated by the fact that in many scientific disciplines, mechanistic explanations are abundant. Because our answer to the second question is negative, our last question is ‘What kind of explanation do quantum mechanical models of atom provide?’ By addressing these questions, we shed light on the nature of an important type of chemical explanation. (shrink)

The history of the diffusion and confirmation of Mendeleev’s periodic table of elements has proven to be a challenging testbed for contemporary philosophical debates on the role of predictions in science. More than ten years of fruitful literature came after Scerri and Worrall :407–452, 2001) versus Maher and Lipton ; nevertheless, such a long-lasting debate left quite a few open questions. The aim of this contribution is to go through the various cases that emerged during the debate, in an (...) effort to explain them coherently in a weak predictivist perspective. Maher’s early account—according to which the astounding success of the major predictions alone was enough to explain the confirmation of the periodic table—can now be replaced by a more balanced and thorough picture, where both predictions and accommodations do weight. (shrink)

The lanthanide elements from lanthanum to lutetium inclusive are incorporated into the body of the periodic table. They are subdivided into three sub-groups according to their important oxidation states: La to Sm, Eu to Tm, Yb and Lu, so that Eu and Yb fall directly below Ba; La, Gd, Lu form a column directly below Y; Ce and Tb fall in a vertical line between Zr and Hf. Pm falls below Tc; both are radioactive, and not naturally occurring. The (...) elements with easily attained 2+ and 4+ oxidation states are grouped and clearly differentiated. Gadolinium has an important position as the centre of four triads in the block of elements that surround it– La, Gd, Lu; Ba, Gd, Hf; Eu, Gd, Tb; Yb, Gd, Ce. This new arrangement has the advantages of compactness, simplicity and clarity – there are no tie lines; and important oxidation states of these metals are emphasized. The actinides are also accommodated within this system, and element 114 falls naturally below lead in Group 14. (shrink)

There are many- not just one- periodic laws in chemistry. These laws correspond to non-accidental regularity relations about physical and chemical properties of (sets of) chemical elements. I support this by showing how these regularity relations can be understood from the perspective of a philosophical analysis of laws. Specifically, I show that these relations instantiate standard features associated with laws; they can be spelled out in terms of two standard accounts of laws; and, they can coherently figure in debates (...) about the reality of laws as plausible candidates of ceteris paribus laws. (shrink)

It is argued that the conventional descriptions of chemical bonds as covalent, ionic, metallic, and Van der Waals are compromising the usefulness of quantum mechanics in the synthesis and design of new molecules and materials. Parallels are drawn between the state of chemistry now and when the idea that phlogiston was an element impeded the development of chemistry. Overcoming the current obstacles will require new methods to describe molecular structure and bonding, just as new concepts were needed before (...) the phlogiston theory could be set aside. (shrink)

There is now a considerable body of published work on the epistemology of modern chemistry, especially with regard to the nature of quantum chemistry. In addition, the question of the metaphysical underpinnings of chemistry has received a good deal of attention. The present article concentrates on metaphysical considerations including the question of whether elements and groups of elements are natural kinds. It is also argued that an appeal to the metaphysical nature of elements can help clarify the re-emerging controversies (...) among chemists regarding the placement of the elements hydrogen and helium in the periodic system and the question of whether there exists a best form of the periodic table. (shrink)

A modification of the regular medium-form periodic table is presented in which certain elements are placed in more than one position. H is included at the top of both the alkali metals and the halogens; He is above Be and above Ne. The column of noble gases is duplicated as Groups O and 18. The elements of the second and third periods are duplicated above the transition metals. This arrangement displays more patterns and connections between the elements than are (...) seen in the regular format. It fits more facts and so gives better guidance to useful predictions. (shrink)

The philosopher of chemistry Andrea Woody has recently published a wide-ranging article concerning the turn to practice in the philosophy of science. Her primary example consists of the use of different forms of representations by Lothar Meyer and Mendeleev when they presented their views on chemical periodicity. Woody believes that this distinction can cast light on various issues including why Mendeleev was able to make predictions while Meyer was not. Secondly, she claims that it can clarify the much-debated question (...) concerning the relative values of prediction and accommodation of data in the way that the periodic system was accepted. Thirdly, Woody believes that such differences in the representation of periodicity can be used to argue for the explanatory nature of the periodic table in contrast with the more traditional view that the periodic table is not explanatory. (shrink)

Group 3 as Sc–Y–La, rather than Sc–Y–Lu, dominates the literature. The history of this situation, including involvement by the IUPAC, is summarised. I step back from the minutiae of physical, chemical, and electronic properties and explore considerations of regularity and symmetry, natural kinds, and quantum mechanics, finding these to be inconclusive. Continuing the theme, a series of ten interlocking arguments, in the context of a chemistry-based periodic table, are presented in support of lanthanum in Group 3. In (...) so doing, I seek to demonstrate a new way of thinking about this matter. The last of my ten arguments is recast as a twenty-word categorical philosophical (viewpoint-based) statement. (shrink)

The Periodic Table of Elements is one of the greatest achievements of the human intellect but is far from a finished work. Generations of chemists and physicists have improved on it, in light of the discovery of new elements and advancements in the domain of Quantum Mechanics. Specially, the role of the four quantum numbers that dictates the distribution of the elements throughout the Table has been clarified. However, as the Table grew older and venerable, a (...) tradition developed that froze its overall shape, obfuscating somewhat the comprehension of its underlying principles. Proposals of reforming it has been made but face the opposition of scientists, professionals and educators who are comfortable with the Table as it has been for several decades. Here, the author advocates for possible alternatives, discuss potential advantages and answer to some criticisms on them. (shrink)

The concept of a chemical element is foundational within the field of chemistry, but there is wide disagreement over its definition. Even the International Union for Pure and Applied Chemistry (IUPAC) claims two distinct definitions: a species of atoms versus one which identifies chemical elements with the simple substances bearing their names. The double definition of elements proposed by the International Union for Pure and Applied Chemistry contrasts an abstract meaning and an operational one. Nevertheless, the philosophical aspects of this (...) notion are not fully captured by the IUPAC definitions, despite the fact that they were crucial for the construction of the Periodic Table. Although rich scientific literature on the element and the periodic table exists as well as a recent growth in the philosophy of chemistry, scholars are still searching for a definitive answer to this important question: What is an element? (shrink)

The current status of explanation worked out by Physics for the Periodic Law is considered from philosophical and methodological points of view. The principle gnosiological role of approximations and models in providing interpretation for complicated systems is emphasized. The achievements, deficiencies and perspectives of the existing quantum mechanical interpretation of the Periodic Table are discussed. The mainstream ab initio theory is based on analysis of selfconsistent one-electron effective potential. Alternative approaches employing symmetry considerations and applying group theory (...) usually require some empirical information. The approximate dynamic symmetry of one-electron potential casts light on the secondary periodicity phenomenon. The periodicity patterns found in various multiparticle systems (atoms in special situations, atomic nuclei, clusters, particles in the traps, etc) comprise a field for comparative study of the Periodic Laws found in nature. (shrink)

Differing views on reduction are briefly reviewed and a suggestion is made for a working definition of 'approximate reduction'. Ab initio studies in quantum chemistry are then considered, including the issues of convergence and error bounds. This includes an examination of the classic studies on CH2 and the recent work on the Si2C molecule. I conclude that chemistry has not even been approximately reduced.

One of the consequences of the renewed interest in philosophical aspects of chemistry has been the corresponding renewed interest in the periodic system of the elements which embodies so much chemical knowledge in an implicit form.We have therefore decided to further promote scholarship on the periodic system by compiling a bibliography of previously published material. As the title of this article implies, we restrict ourselves to secondary sources. Readers interested in primary material can consult a number of useful (...) references for this purpose. These include the classical treatment on the History of the periodic system by van Spronsen as well as Mazurs’s compilation of over 700 forms of the periodic system. Mazurs also includes a detailed bibliography of articles and books in several different languages. Additional sources of primary articles which come to mind include David Knight’s Classics in the History of Chemistry, Carmen Giunta’s web pages for the history of chemistry and entries under individual scientists in the Dictionary of Scientific Biography. Turning to the present compilation we do not claim this to be a comprehensive list, since it partly reflects the interests of the senior author (E.R.S.), namely the relationship between the periodic system and quantum mechanics. For example, in addition to articles specifically on the periodic system we include a number of articles which deal with the related themes of electronic configurations of the elements. This bias also explains the disproportionate number of references to the work of the senior author.We have tried to include as many as possible of the articles on the periodic system which have appeared in the philosophy of science literature. These include Bensaude, Christie, Hettema and Kuipers, Kultgen, Lipton, Maher, Scerri, Shapere and Sundaram, among others. (shrink)

To this day, a hundred and fifty years after Mendeleev's discovery, the overal structure of the periodic system remains unaccounted for in quantum-mechanical terms. Given this dire situation, a handful of scientists in the 1970s embarked on a quest for the symmetries that lie hidden in the periodic table. Their goal was to explain the table's structure in group-theoretical terms. We argue that this symmetry program required an important paradigm shift in the understanding of the nature of (...) chemical elements. The idea, in essence, consisted of treating the chemical elements, not as particles, but as states of a superparticle. We show that the inspiration for this came from elementary particle physics, and in particular from Heisenberg's suggestion to treat the proton and neutron as different states of the nucleon. We provide a careful study of Heisenberg's last paper on the nature of elementary particles, and explain why the Democritean picture of matter no longer applied in modern physics and a Platonic symmetry-based picture was called for instead. We show how Heisenberg's Platonic philosophy came to dominate the field of elementary particle physics, and how it found its culmination point in Gell-Mann's classification of the hadrons in the eightfold way. We argue that it was the success of Heisenberg's approach in elementary particle physics that sparked the group-theoretical approach to the periodic table. We explain how it was applied to the set of chemical elements via a critical examination of the work of the Russian mathematician Abram Ilyich Fet the Turkish-American physicist Asim Orhan Barut, before giving some final reflections. (shrink)

After Heitler and London published their pioneering work on the application of quantum mechanics to chemistry in 1927, it became an almost unquestioned dogma that chemistry would soon disappear as a discipline of its own rights. Reductionism felt victorious in the hope of analytically describing the chemical bond and the structure of molecules. The old quantum theory has already produced a widely applied model for the structure of atoms and the explanation of the periodic system. This (...) paper will show two examples of the entry of quantum physics into more classical fields of chemistry: inorganic chemistry and physical chemistry. Due to their professional networking, George Hevesy and Michael Polanyi found their ways to Niels Bohr and Fritz London, respectively, to cooperate in solving together some problems of classical chemistry. Their works on rare earth elements and adsorption theory throws light to the application of quantum physics outside the reductionist areas. They support the heuristic and persuasive value of quantum thinking in the 1920–1930s. Looking at Polanyi’s later oeuvre, his experience with adsorption theory could be a starting point of his non-justificationist philosophy. (shrink)

The concept of major scientific advances occurring as a short-term ‘revolutionary’ change in thinking interspersed by long periods of so-called ‘normal’ science seems to be losing ground to more ecological models, which are more inimical of the twists and turns of life. From this idea it is a short step to charting science’s progress against stages used in fictional storytelling, which after all is life-based. This paper explores the development of the periodic table in terms of the achievement of (...) a fictional ‘quest’, and finds the stages of such a story are well represented. While Mendeleev or perhaps Meyer might be considered by some to be the hero of the quest, its first stage—the call—is represented by the Karlsruhe conference in 1860, with an international cast of ‘companions’ and ‘helpers’ who contributed to the Table’s early development. The ‘journey’ may have been frustrated by lack of appropriate data and understanding of concepts, but the ‘arrival’ phase is clearly marked by the award of the Davy medal jointly to Mendeleev and Meyer in 1882, Throughout these stages there are lesser, although still significant contributions made by “little people” of science to the overall progress of the Table. The end of the journey is not the end of the quest: the discovery of new elements—“new ordeals”—and their incorporation into an increasing range of types and styles of periodic table, which—akin to the “life-renewing goal” of the fictional quest—continue. (shrink)

Periodic tables (PTs) are the ‘ultimate paper tools’ of general and inorganic chemistry. There are three fields of open questions concerning the relation between PTs and physics: (i) the relation between the chemical facts and the concept of a periodic system (PS) of chemical elements (CEs) as represented by PTs; (ii) the internal structure of the PS; (iii)␣The relation between the PS and atomistic quantum chemistry. The main open questions refer to (i). The fuzziness of the concepts (...) of chemical properties and of chemical similarities of the CE and their compounds guarantees the autonomy of chemistry. We distinguish between CEs, Elemental Stuffs and Elemental Atoms. We comment on the basic properties of the basic elements. Concerning (ii), two sharp physical numbers (nuclear charge and number of valence electrons) and two coarse fuzzy ranges (ranges of energies and of spatial extensions of the atomic orbitals, AOs) characterize the atoms of the CEs and determine the two-dimensional structure of the PS. Concerning (iii), some relevant ‘facts’ about and from quantum chemistry are reviewed and compared with common ‘textbook facts’. What counts in chemistry is the whole set of nondiffuse orbitals in low-energy average configurations of chemically bonded atoms. Decisive for the periodicity are the energy gaps between the core and valence shells. Diffuse Rydberg orbitals and minute spin–orbit splittings are important in spectroscopy and for philosophers, but less so in chemical science and for the PS. (shrink)

A critique is given of the attempt by Hettema and Kuipers to formalize the periodic table. In particular I dispute their notions of identifying a naïve periodic table with tables having a constant periodicity of eight elements and their views on the different conceptions of the atom by chemists and physicists. The views of Hettema and Kuipers on the reduction of the periodic system to atomic physics are also considered critically.

Diagonal relationships in the periodic table were recognized by both Mendeléev and Newlands. More appropriately called isodiagonal relationships, the same three examples of lithium with magnesium, beryllium with aluminum, and boron with silicon, are commonly cited. Here, these three pairs of elements are discussed in detail, together with evidence of isodiagonal linkages elsewhere in the periodic table. General criteria for defining isodiagonality are proposed.

We briefly describe in this paper the passage from Mendeleev’s chemistry (1869) to atomic physics (in the 1900’s), nuclear physics (in 1932) and particle physics (from 1953 to 2006). We show how the consideration of symmetries, largely used in physics since the end of the 1920’s, gave rise to a new format of the periodic table in the 1970’s. More specifically, this paper is concerned with the application of the group SO(4,2)⊗SU(2) to the periodic table of chemical elements. (...) It is shown how the Madelung rule of the atomic shell model can be used to set up a periodic table that can be further rationalized via the group SO(4,2)⊗SU(2) and some of its sub-groups. Qualitative results are obtained from this nonstandard table. (shrink)

Since Mendeleev’s discovery in 1869, the periodic table has figured as the ultimate paper tool in chemical research. It has proved to be a vital research instrument in the arsenal of the chemical community. No chemistry textbook, lecture theatre or scientific laboratory is complete without a copy of the periodic table of the elements. -/- This however, should not necessarily imply that the periodic table has never had to contend with problems. In this thesis, the history of (...) the accommodation of the rare-earth elements in the periodic table will be addressed. When Mendeleev published his periodic table in 1869, the rare earths already constituted a major obstacle. Mendeleev was able to include only four members of the rare earths and he experienced great difficulties in positioning these elements. Question marks and wrong atomic weights reigned in the last rows of Mendeleev’s system. -/- This problematic accommodation quickly grew into one of the most serious threats for the periodic law. For over fifty years, chemists continually struggled with the placement of these maddeningly similar elements. As a consequence, a lot of chemists started to question the validity of the periodic law, but others took it as a sign that the concept of a chemical element had to be reconsidered. As a result, this work intends to retrace the mutual influence of the philosophical ideas about the nature of chemical elements and the development of the periodic table from its inception in 1869 to the discovery of Moseley’s law in 1913 and Bohr’s publication of his landmark paper On the Constitution of Atoms and Molecules. -/- The aim of this thesis is to show how, on the one hand, the periodic table (as a research instrument) helped in reformulating the contemporary ideas about chemical elements, and how it aided in developing a new research program in order to resolve the rare earth crisis. On the other hand, the question will be taken up to what extent Crookes’ evolutionary ideas about meta elements helped in saving the periodic table from a severe downfall by solving the gnawing problem of the rare-earth elements. In particular, this work will also focus on the investigations of the Czech chemist, Bohuslav Brauner. It will be shown how Brauner, under the influence of Crookes’ ideas, was led to his formulation of the Asteroid Hypothesis, according to which all the rare-earth elements should be placed in a single case of the periodic table. (shrink)

A quick question! Who’s the first name that comes to mind when the periodic table is mentioned? Dmitrii Ivanovich Mendeleev is the obvious and universal answer. And the second name? Most of you would probably agree with my answer: Eric R. Scerri, Lecturer in Chemistry and History and Philosophy of Science at the University of California, Los Angeles, and founding editor of this journal, devoted to the philosophy of chemistry, another of his specialties.Through the years I have (...) followed Scerri’s work on the periodic table, reading his numerous articles and reviewing his two previous books (Scerri 2007; Laing and Kauffman 2007; Scerri 2009; Kauffman 2011). In his latest book he comprehensively but succinctly examines this true cultural iconic symbol of science that is used by artists, advertisers, and of course, scientists in all fields. It is almost as familiar to the general public as the chemical formula for water, and an understanding and appreciation for it is essential to the physi. (shrink)

Demarcation of elements for two subsets appears to be the most fundamental approach to their classification. If one draws a vertical straight line through the middle of each block of elements in the Periodic table, all the elements are divided into two subsets: “early” and “later”. For example, in the d-block, the early ones are Sc–Mn, and the late ones, respectively, are Fe–Zn. Later elements partially repeat the properties of the early ones, and this is defined as the internal (...) periodicity. Another criterion for dividing the elements into two subsets is the evenness and oddness of the sum of n + l, where n is the principal quantum number, and l is the orbital quantum number for the outer electron subshells. Properties of the odd elements are closer to each other than to properties of even elements, and vice versa. This regularity is manifested as the secondary periodicity. The history of concepts, which considered the existence of subsets as well as of inner and secondary periodicities, is discussed. The features of the electronic structure, which underlie the existence of subsets, are considered. The existence of subsets was depicted earlier by dividing the periodic table into two tables or by applying a mirror-symmetric table. Small changes are proposed in the conventional Periodic table, allowing to reflect the existence of the considered subsets. (shrink)

The debate about the relative epistemic weights carried in favour of a theory by predictions of new phenomena as opposed to accommodations of already known phenomena has a long history. We readdress the issue through a detailed re-examination of a particular historical case that has often been discussed in connection with it—that of Mendeleev and the prediction by his periodic law of the three ‘new’ elements, gallium, scandium and germanium. We find little support for the standard story that these (...) predictive successes were outstandingly important in the success of Mendeleev's scheme. Accommodations played an equal role—notably that of argon, the first of the ‘noble gases’ to be discovered; and the methodological situation in this chemical example turns out to be in interesting ways different from that in other cases—invariably from physics—that have been discussed in this connection. The historical episode when accurately analysed provides support for a different account of the relative weight of prediction and accommodation—one that is further articulated here. (shrink)

There has been plenty of empirical evidence which shows that the single-particle picture holds to a good approximation in atomic nuclei. In this picture, protons and neutrons move independently inside a mean-field potential generated by an interaction among the nucleons. This leads to the concept of nuclear shells, similar to the electronic shells in atoms. In particular, the magic numbers due to closures of the nucleonic shells, corresponding to noble gases in elements, have been known to play an important role (...) in nuclear physics. Here we propose a periodic table for atomic nuclei, in which the elements are arranged according to the known nucleonic shells. The nuclear periodic table clearly indicates that nuclei in the vicinity of the magic numbers can be understood in terms of a shell closure with one or two additional nucleons or nucleon holes, while nuclei far from the magic numbers are characterized by nuclear deformation. (shrink)

An Example of Teaching of Chemistry Before and After Mendeleev’s 1869 Periodic Table of Elements is presented. Prior to Mendeleev’s publication in 1869, only 63 elements were known. The ensuing discovery of the electron and the correspondence of the number of electrons to equivalent weight and atomic number is of singular importance to the impact of the Periodic Table of Elements and the way modern chemistry is taught. Without the identity of the electron and its alliance to atomic (...) number, modern teaching of chemistry would be very different. Without it concepts of electronic configuration, oxidation and reduction, polarization, intermolecular interactions, types of bonding, Lewis acid/base definition, etc. would disappear in our vernacular. Thus, we trace the origin of the electron. (shrink)

Many different arguments have been put forward in order to assign the best place for a given element within Mendeleev's Table: its spectroscopy, its chemical activity, the crystalline structure of its solid state, etc. We here propose another criterion; the nature of the few body corrections to the pairwise additive energy. This argument is used here to address a question often brought forward by Eric Scerri in Foundations of Chemistry, namely the rightful place of helium; either above the column of (...) the alkaline earths (beryllium, etc.) or rather above the noble gas elements. (shrink)

We interpret the philosophy of Niels Bohr as related to the so called ''linguistic turn'' and consider paraconsistency in the light of the Bohrian notion of complementarity. Following [16], Jean-Yves Beziau has discussed the seemingly contradictory perspectives found in the quantum mechanical double slit experiment in terms of paraconsistent view-points [7, 8]. This interpretation goes in line with the well known Bohrian Neo-Kantian epistemological account of quantum mechanics. In the present paper, we put forward the idea (...) that one can also consider, within quantum mechanics and departing from the philosophy of the danish physicist, a more radical paraconsistency found within one of the main formal elements of the theory, namely, quantum superpositions. We will argue that, rather than epistemological, the contradictions found within quantum superpositions could be interpreted as ontological contradictions. (shrink)

The UNBELIEVABLE similar ideas between Theise and Menas’ ideas (2016) and my ideas (2002-2008) in Physics and Cognitive Neuroscience and Philosophy (the mind-brain problem, quantum mechanics, etc.) -/- (2016) Theise D. Neil (Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY, USA) and Kafatos C. Menas (bDepartment of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA; cSchmid College of Science & Technology, Chapman University, Orange, CA, USA) (2016), REVIEW - (...) Fundamental awareness: A framework for integrating science, philosophy and metaphysics, in COMMUNICATIVE & INTEGRATIVE BIOLOGY, 2016, VOL. 9, NO. 3, e1155010 (19 pages), http://dx.doi.org/10.1080/19420889.2016.1155010 -/- A friend of mine indicated me the strike similarities between Theise and Kafatos’ ideas in their book (Fundamental awareness: A framework for integrating science, philosophy and metaphysics) and my ideas in 2002-20008! I do not have access to this book, but I investigate the ideas that are in a review about this work. Let me introduce the abstract of that Review: -/- The ontologic framework of Fundamental Awareness proposed here assumes that non-dual Awareness is foundational to the universe, not arising from the interactions or structures of higher level phenomena. The framework allows comparison and integration of views from the three investigative domains concerned with understanding the nature of consciousness: science, philosophy, and metaphysics. In this framework, Awareness is the underlying reality, not reducible to anything else. Awareness and existence are the same. As such, the universe is non-material, self-organizing throughout, a holarchy of complementary, process driven, recursive interactions. The universe is both its own first observer and subject. Considering the world to be non-material and comprised, a priori, of Awareness is to privilege information over materiality, action over agency and to understand that qualia are not a “hard problem,” but the foundational elements of all existence. These views fully reflect main stream Western philosophical traditions, insights from culturally diverse contemplative and mystical traditions, and are in keeping with current scientific thinking, expressible mathematically. (shrink)

The debate about the relative epistemic weights carried in favour of a theory by predictions of new phenomena as opposed to accommodations of already known phenomena has a long history. We readdress the issue through a detailed re-examination of a particular historical case that has often been discussed in connection with it-that of Mendeleev and the prediction by his periodic law of the three 'new' elements, gallium, scandium and germanium. We find little support for the standard story that these (...) predictive successes were outstandingly important in the success of Mendeleev's scheme. Accommodations played an equal role-notably that of argon, the first of the 'noble gases' to be discovered; and the methodological situation in this chemical example turns out to be in interesting ways different from that in other cases-invariably from physics-that have been discussed in this connection. The historical episode when accurately analysed provides support for a different account of the relative weight of prediction and accommodation-one that is further articulated here. (shrink)

Carlo Rovelli's relational interpretation of quantum mechanics holds that a system's states or the values of its physical quantities as normally conceived only exist relative to a cut between a system and an observer or measuring instrument. Furthermore, on Rovelli's account, the appearance of determinate observations from pure quantum superpositions happens only relative to the interaction of the system and observer. Jeffrey Barrett ([1999]) has pointed out that certain relational interpretations suffer from what we might call the (...) ‘determinacy problem', but Barrett misclassifies Rovelli's interpretation by lumping it in with Mermin's view, as Rovelli's view is quite different and has resources to escape the particular criticisms that Barrett makes of Mermin's view. Rovelli's interpretation still leaves us with a paradox having to do with the determinacy of measurement outcomes, which can be accepted only if we are willing to give up on certain elements of the ‘absolute’ view of the world. (shrink)