Psychologists and philosophers tend to treat expertise as a property of special individuals. These are individuals who have devoted much more time than the general population to the acquisition of their specific expertises. They are often said to pass through stages as they move toward becoming experts, for example, passing from an early stage, in which they follow self-conscious rules, to an expert stage in which skills are executed unconsciously. This approach is ‘one-dimensional’. Here, two extra dimensions are added. (...) They are drawn from the programme known as Studies of Expertise and Experience (SEE) and its ‘Periodic Table of Expertises’. SEE, which is sociological, and/or Wittgensteinian, in inspiration, takes expertise to be the property of groups; there are ‘domains’ of expertise. Under SEE, level of expertise grows with embedding in the society of domain experts; the key is the transmission of domain-specific tacit knowledge. Thus, one extra dimension is degree of exposure to tacit knowledge. Under SEE, domains can be big or small so there can be ‘ubiquitous tacit knowledge’, such as natural-language-speaking or other elements of general social behaviour, which belong to every member of a society. The second extra dimension is, therefore, ‘esotericity’. The resulting three-dimensional ‘expertise-space’ can be explored in a number of ways which reveal the narrowness of the analysis and the mistakes that have been made under the one-dimensional model. (shrink)

In case of that human civilization was viewed as an integrated organism, the Periodic Table of the Civilizations (PTOC in short) has been formulated and recommended based on the development level and periodicity of core elements of human civilization. It divides the frontier process of the human civilization from the birth of humankind to the end of twenty-first century into 4 periods and 16 stages, and in which four periods include that of primitive culture, agricultural civilization, industrial civilization (...) and knowledge civilization orderly, and each period includes four stages, that is, start, developing, maturing and transition stages sequentially. There are three approaches for the arrangements of the PTOC, that is, simple, vertical and horizontal tables. The big period of earth civilization refers to that from the primitive culture to the knowledge civilization, and then big period of space civilization will begin with the astronautic civilization. The first modernization witnesses the great changes and transformation from the traditional agricultural to the modern industrial civilization, and then second modernization from the modern industrial to the higher modern knowledge civilization. The periodic table, coordinate system and roadmap of human civilization and world modernization have been formulated to describe the relationship between them. (shrink)

This manuscript aims to systematically consider the main periodicity and additional (secondary, internal, and tetrad) periodicities using a uniform approach. The main features are summarized in table form. The history of the origin and development of these concepts is discussed. It is described how these periodicities manifest themselves and how they are determined at the experimental and theoretical levels. Areas of manifestation of these periodicities are outlined. As the general approach to explaining internal periodicity, attention is drawn to the (...) symmetry of the quantum number S of atoms and the principle of equivalence of electrons and holes. Arguments are presented in favor of a more correct classification of the tetrad effect as tetrad periodicity, and an overview of this regularity is provided. A small modification of the conventional Periodic table is proposed, which reflects all the mentioned periodicities. (shrink)

Within contemporary personality psychology there is widespread consensus that, at long last, the basic elements of "the" human personality have been empirically discovered, and that the systematic search for the underlying causes and consequences of personality differences can be pursued on this basis. The putatively basic trait dimensions are neuroticism, extraversion, openness, agreeableness, and conscientiousness, and are referred to collectively as "the Big Five." In the present article, this perspective on the psychology of personality is examined critically and found wanting. (...) It is argued that neither the "Big Five" framework in particular nor trait "psychology" more generally is adequate as the basis for a scientific psychology of the human person. 2012 APA, all rights reserved). (shrink)

The aim of this paper is to indicate the systematic place of arguments based on the concept of analogy within the theoretical framework of the Periodic Table of Arguments, a new method for describing and classifying arguments that integrates traditional dialectical accounts of arguments and fallacies and rhetorical accounts of the means of persuasion (logos, ethos, pathos) into a comprehensive framework. The paper begins with an inventory of existing approaches to arguments based on analogy, similarity and adjacent concepts. (...) Then, the theoretical framework of the table will be expounded and several concrete examples of arguments based on these concepts will be analyzed in terms of the framework. Finally, the results of these analyses will be summarized and it will be indicated how they can be refined in further research related to the Periodic Table of Arguments. (shrink)

To become an expert in a technical domain means acquiring the tacit knowledge pertaining to the relevant domain of expertise, at least, according to the programme known as “Studies of Expertise and Experience” (SEE). We know only one way to acquire tacit knowledge and that is through some form of sustained social contact with the group that has it. Those who do not have such contact cannot acquire the expertise needed to make technical judgments. They can, however, use social expertise (...) to judge between experts or expert claims. Where social expertise is used to make technical judgments we refer to it as “transmuted expertise”. The various kinds of transmuted expertise are described and analysed. (shrink)

No one knows yet how to organize, in a simple yet predictive form, the knowledge concerning the anatomical, biophysical, and molecular properties of neurons that are accumulating in thousands of publications every year. The situation is not dissimilar to the state of Chemistry prior to Mendeleev's tabulation of the elements. We propose that the patterns of presence or absence of axons and dendrites within known anatomical parcels may serve as the key principle to define neuron types. Just as the positions (...) of the elements in the periodic table indicate their potential to combine into molecules, axonal and dendritic distributions provide the blueprint for network connectivity. Furthermore, among the features commonly employed to describe neurons, morphology is considerably robust to experimental conditions. At the same time, this core classification scheme is suitable for aggregating biochemical, physiological, and synaptic information. (shrink)

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 (...) 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)

The thesis is: the “periodic table” of “dark matter” is equivalent to the standard periodic table of the visible matter being entangled. Thus, it is to consist of all possible entangled states of the atoms of chemical elements as quantum systems. In other words, an atom of any chemical element and as a quantum system, i.e. as a wave function, should be represented as a non-orthogonal in general (i.e. entangled) subspace of the separable complex Hilbert space (...) relevant to the system to which the atom at issue is related as a true part of it. The paper follows previous publications of mine stating that “dark matter” and “dark energy” are projections of arbitrarily entangled states on the cognitive “screen” of Einstein’s “Mach’s principle” in general relativity postulating that gravitational field can be generated only by mass or energy. (shrink)

The periodic table may be seen as the most successful example of inquiry in the history of science, both in terms of practical application and theoretic understanding. As such, it serves as a model for truth as it emerges from inquiry. This paper offers a sketch of a central moment in the history of chemistry that illustrates an intuitive metamathematical construction, a model of emerging truth. The MET, reflecting the structure the surrounds the periodic table, attempts (...) to capture the salient epistemological elements that warrant truth claims based on sets of models that are progressive in light of both empirical and theoretical advance seen over time. (shrink)

In the early modern period, botany still remained a relatively new arrival at the top table of knowledge. Much botanical work was not done in universities, colleges, academies, laboratories, or botanic gardens, but behind the walls of different kinds of gardens – of the royalty as well as of common people, of monasteries as well as public gardens. By following the circula­tion of oranges, especially taking into consideration the role of Portugal as a turn­table, this paper sheds light (...) on several of the unexpected ways in which the history of botany and horticulture and the history of gardens encountered in the early modern world. The history of oranges has often made reference to the acclimatization of this citrus fruit in Europe and its transplantation to the New World. However, very few works have addressed the dissemination of oranges from the Iberian Peninsula. In this paper, I argue for a change in perspective by stressing the role played by the Portuguese on acclimatization and dissemination of oranges from Asia to Portugal, and from this country to the Old and New Worlds. I also stress the role Portugal played in building and popularizing horticultural expertise for orange growth and its corresponding botanical knowledge. (shrink)

Helium and neon, the two lightest noble gases, have been traditionally positioned by IUPAC in the Group 18 of the Periodic Table of Elements, together with argon, and other unreactive or moderately reactive gaseous elements (krypton, xenon, radon), and oganesson. In this account we revive the old discussion on the possible placement of helium in the Group 2, while preserving the position of neon in Group 18. We provide quantum-chemical arguments for such scenario—as well as other qualitative and (...) quantitative arguments—and we describe previous suggestions in the literature which support it or put it into question. To this author’s own taste, He should be placed in Group 2. (shrink)

A large variety of periodic tables of the chemical elements have been proposed. It was Mendeleev who proposed a periodic table based on the extensive periodic law and predicted a number of unknown elements at that time. The periodic table currently used worldwide is of a long form pioneered by Werner in 1905. As the first topic, we describe the work of Pfeiffer, who refined Werner’s work and rearranged the rare-earth elements in a separate (...) table below the main table for convenience. Today’s widely used periodic table essentially inherits Pfeiffer’s arrangements. Although long-form tables more precisely represent electron orbitals around a nucleus, they lose some of the features of Mendeleev’s short-form table to express similarities of chemical properties of elements when forming compounds. As the second topic, we compare various three-dimensional helical periodic tables that resolve some of the shortcomings of the long-form periodic tables in this respect. In particular, we explain how the 3D periodic table “Elementouch”, which combines the s- and p-blocks into one tube, can recover features of Mendeleev’s periodic law. Finally we introduce a topic on the recently proposed nuclear periodic table based on the proton magic numbers. Here, the nuclear shell structure leads to a new arrangement of the elements with the proton magic-number nuclei treated like noble-gas atoms. We show that the resulting alignments of the elements in both the atomic and nuclear periodic tables are common over about two thirds of the tables because of a fortuitous coincidence in their magic numbers. (shrink)

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.

Sometimes the right book finds you at the right time, and it shifts your perception of a familiar subject just a little, just enough to make a difference. It reminds you of something important you haven’t thought of in a while, or it shows you a new way of looking at and interacting with the world. Last winter, for me, that book was The Disappearing Spoon, by Sam Kean. I heard a very fuzzy description of the book at a holiday (...) party, something about the periodic table and political history. As someone eternally interested in chemistry and its impact on society at large, I was intrigued. (shrink)

The seventh sign in Charles Peirce’s well-known 10-sign taxonomy of the 1903 Syllabus has received relatively little attention compared to many other types of sign that he described. It is the sign type of “Dicent Indexical Legisigns”, a result of the combinatory strategy of the 3x3 elementary sign aspects defined by the three basic sign trichotomies of Qualisign-Sinsign-Legisign, Icon-Index-Symbol and Rheme-Dicisign-Argument, a new strategy developed by Peirce in that famous text. It is well known how such aspects do not combine (...) freely, hence not resulting in 3 × 3 × 3 = 27 sign types, but only in 10 sign types, due to the application of the rule aptly summarized by Bellucci as “a certain combination... (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)

This paper describes the construction of the Periodic Tables for cations of all elements with charges + 1, + 2, + 3 and anions with charge − 1. The Table for cations+1 differs significantly from other newly constructed Tables and from known Tables, as the d- and f-blocks are inserted into s-block and split it up for two parts. Importantly, a new type of 3d- and 4f-shell contractions has been discovered. The manifestations of secondary periodicity in case of (...) anions is absent or opposite to the manifestations observed for atoms and cations. For kainosymmetric anions, the ionization energies are lowered, which contradicts the theoretical assumptions and experimental data supporting the classical concept of kainosymmetry. Simple formulas are proposed for quantitative description of the manifestations of internal periodicity and kainosymmetry. The regularities of change in these manifestations depending on the charge and the position of ions or atoms in the Periodic Table are established. In the 6th period, the bifurcation in the properties characteristic of the internal periodicity does not occur at usual position, i.e. in the middle of the row from the block of the Periodic Table, but takes place earlier, along with the transition of the electronic configurations p2–p3. In other words, the place of transition from "early" to "late" elements changes. (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)

Sam Kean: The disappearing spoon: and other true tales of madness, love, and the history of the world from the periodic table of the elements Content Type Journal Article Pages 77-77 DOI 10.1007/s10698-010-9101-x Authors Michael Laing, School of Pure and Applied Chemistry, University of KwaZulu-Natal, Durban, 4041 South Africa Journal Foundations of Chemistry Online ISSN 1572-8463 Print ISSN 1386-4238 Journal Volume Volume 13 Journal Issue Volume 13, Number 1.

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.

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)

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)

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.

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)

In a lengthy article E. Scerri and J. Worrall put forward the case for a novel ‘accommodationist’ version of the events surrounding the development of Mendeleef's Periodic Table 1869–1899. However these authors lay undue stress on the fact that President of the Royal Society of London Spottiswoode made absolutely no mention of Mendeleef's famous predictions in the Davy Medal eulogy in 1883 and undue stress on the fact that Cleve's classic 1879 Scandium paper contained an acknowledgement of Mendeleef's (...) prior prediction of eka-boron.They also fail to analyse in any detail the so-called ‘rare earth problem’ which, in the opinion of this author, causes problems for their account but not for a predictivist account. (shrink)

This article carefully analyzes a recent paper by Weisberg in which it is claimed that when Mendeleev discovered the periodic table he was not working as a modeler but instead as a theorist. I argue that Weisberg is mistaken in several respects and that the periodic table should be regarded as a classification, not as a theory. In the second part of the article an attempt is made to elevate the status of classifications by suggesting that (...) they provide a form of ‘side-ways explanation’. (shrink)

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)

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)

In lieu of an abstract, here is a brief excerpt of the content:Reaching the Age of Majority:The Life Trajectory of the CIHR Institute of AgingYves Joanette, Anne Martin-Matthews, Réjean Hebert, and Joanne GoldbergThe Canadian Institutes of Health Research (CIHR) was created in 2001 under the Canadian Institutes of Health Research Act S.C. 2000, c. 6 (Government of Canada, 2000). The creation of CIHR was in follow-up to the Canadian Medical Research Council (MRC) as well as to the National Health Research (...) and Development Program of Health Canada that, up until that point in time, had supported the breadth of health research in Canada. Two important characteristics of CIHR were crucial for the development of research on aging. The first was that CIHR, unlike MRC, was entrusted with the challenge of supporting the whole spectrum of health research, from the basic biomedical perspective to clinical research, research on health services and policies as well as social aspects of health research, not to mention research on ethics and other perspectives (including the science of research). The second characteristic of the nascent CIHR that impacted the community of research on aging was the decision that a small part of the overall CIHR budget would be used to address priority-driven questions or topics (strategic competitions), while the majority of the budget would be invested in grants and awards programs that would be investigator-initiated, as in the time of the MRC (open competition). Since its inception, CIHR has included 13 institutes that are central to the priority-driven actions. Institutes not only play an important convener role within their communities and among their stakeholders, but they are also expected to listen to the needs, gaps and opportunities in their area and to introduce initiatives---most of the time involving more than one Institute---in order to tackle these needs and gaps and to seize upon the opportunities.The Institute of Aging was introduced at the same time as the other 12 Institutes and it is clear that many challenges were awaiting the new Institute since, at that time, research on aging was still in its early years. This article is about the trajectory of the CIHR Institute of Aging in its first 18 years of existence. Having now reached an age that is either the age of majority or quite close to it, it is important to be able to provide a reflection on the evolution of the priorities over this period, while also taking a peek at some of the priorities that will surely come in the near future.The Early Years (2001-2004)The founding Scientific Director of the Institute of Aging was Dr. Réjean Hébert. A well-known and prolific [End Page 1] geriatrician and researcher, Dr. Hébert was the perfect person to launch the Institute. One of his first actions was, in fact, to harmonize the French and English names of the Institute. In French, the name of the Institute focused on Aging (Institut du vieillissement) while, in English, the name of the Institute focused on Healthy Aging. The CIHR Institute of Healthy Aging thus became the CIHR Institute of Aging in all versions of its documentation. But above and beyond this important name change, the real work of Dr. Hebert, accompanied by the first Institute Advisory Board1, chaired by Prof. Dorothy Pringle, was to identify the gaps, the needs and the opportunities. After a rigorous process came the first Strategic Plan of the CIHR Institute of Aging, which was clearly influenced by Dr. Réjean Hébert's vision of the aging population as an opportunity, instead of a catastrophe, for our society that comes, of course, with its own challenges. Dr. Hébert left CIHR during his first mandate as he was called upon to become the Dean of his Faculty, and then went on to become the first CIHR Scientific Director to sit as a Minister of Health and Social Services in the Québec Government. The main outcomes of Dr. Hebert's years (2001-2004) can be summarized as follows2.• Organizing many workshops and meetings to ensure that the Institute of Aging would become the premier national convener for research on aging, bridging between disciplines... (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.

In a paper from 2001, Michael C. Rea considers the question of what pornography is. First, he examines a number of existing definitions of ‘pornography’ and after having rejected them all, he goes on to present his own preferred definition. In this short paper, I suggest a counterexample to Rea’s definition. In particular, I suggest that there is something that, on the one hand, is pornography according to Rea’s definition, but, on the other hand, is not something that we would (...) intuitively describe as being an instance of pornography. (shrink)

This chapter gives an overview of the evolution of the position of the rare-earth elements in the periodic system, from Mendeleev’s time to the present. Three fundamentally different accommodation methodologies have been proposed over the years. Mendeleev considered the rare-earth elements as homologues of the other elements. Other chemists looked upon the rare earths as forming a special intraperiodic group and therefore clustered the rare-earth elements in one of the groups of the periodic table. Still others adhered (...) to the intergroup accommodation of the rare earths, according to which the rare-earth elements do not show any relationship with the other elements, so that they had to be placed within the periodic table as a separate family of elements. The intergroup accommodation became the preferred one in the twentieth century. The advantages and disadvantages of the different representations of the modern periodic table are discussed. (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 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)

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.

Several attempts have recently been made to point to ‘the proper place’ for hydrogen in the Periodic Table of the elements. There are altogether five different types of arguments that lead to the following conclusions: hydrogen should be placed in group 1, above lithium; hydrogen should be placed in group 17, above fluorine; hydrogen is to be placed in group 14, above carbon; hydrogen should be positioned above both lithium and fluorine and hydrogen should be treated as a (...) stand-alone element, in the center of the Periodic Table. Although all proposals are based on arguments, not all of them sound equally convincing. An attempt is made, after critical reexamination of the arguments offered, to hopefully point to the best possible choice for the position of hydrogen. A few words are also mentioned on the structure of the Periodic Table and the attempts to reorganize it. (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 basis of the Periodic Table is discussed. Electronic configuration recurs in only 21 out of the 32 groups. A better basis is derived by considering the highest classical valency (v) exhibited by an element and a new measure, the highest valency in carbonyl compounds (v*). This leads to a table based on the number of outer electrons possessed by an atom (N) and the number of electrons required for it to achieve an inert (noble) gas configuration (...) (N*). Periodicity of these is nearly complete. The new basis helps to settle the question of the best form of table and related issues. (shrink)

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)

This article updates the author’s 1982 argument that lutetium and lawrencium, rather than lanthanum and actinium, should be assigned to the d-block as the heavier analogs of scandium and yttrium, whereas lanthanum and actinium should be considered as the first members of the f-block with irregular configurations. This update is embedded within a detailed analysis of Lavelle’s abortive 2008 attempt to discredit this suggestion.

Historians and philosophers of science generally conceptualize scientific progress to be dichotomous, viz., experimental observations lead to scientific laws, which later facilitate the elaboration of explanatory theories. There is considerable controversy in the literature with respect to Mendeleev’s contribution to the origin, nature, and development of the periodic table. The objectives of this study are to explore and reconstruct: a) periodicity in the periodic table as a function of atomic theory; b) role of predictions in scientific (...) theories and its implications for the periodic table; and c) Mendeleev’s contribution: theory or an empirical law? The reconstruction shows that despite Mendeleev’s own ambivalence, periodicity of properties of chemical elements in the periodic table can be attributed to the atomic theory. It is argued that based on the Lakatosian framework, predictions play an important role in the development of scientific theories. In this context, Mendeleev’s predictions played a crucial role in the development of the periodic table. Finally, it is concluded that Mendeleev’s contribution can be considered as an “interpretative” theory which became “explanatory” after the periodic table was based on atomic numbers.Author Keywords: Periodic table; Mendeleev’s contribution; Theory; Empirical law; Interpretative theory. (shrink)

This is a comment on the paper by Barnes and the responses from Scerri and Worrall, debating the thesis that a fact successfully predicted by a theory is stronger evidence than a similar fact known before the prediction was made. Since Barnes and Scerri both use evidence presented in my paper on Mendeleev’s periodic law to support their views, I reiterate my own position on predictivism. I do not argue for or against predictivism in the normative sense that philosophers (...) of science employ, rather I describe how scientists themselves use facts and predictions to support their theories. I find wide variations, and no support for the assumption that scientists use a single ‘Scientific Method’ in deciding whether to accept a proposed new theory.Keywords: Predictivism; Novel predictions; Accommodation; Periodic law; Periodic table; Dmitri Mendeleev. (shrink)

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)