In a lengthy article E. Scerri and J. Worrall (2001) 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)
The philosophical significance of Dmitri Mendeleevâ€™s successful predictions of the properties of gallium and scandium vis a vis the acceptance of the Periodic Table 1874â€“1886 has been debated recently. This author presents evidence that De Boisbaudran and Cleve both respectively predicted the possible existence of gallium and scandium, but on the basis of the old TRIAD methodology. This suggests that these successful Mendeleev predictions were therefore not independent corroboration of the concept of the Periodic System. Instead the significantly independent predictive (...) successes for Mendeleevâ€™s system were (a) the determination of the atomic weight of the known element uranium as 240 instead of the previously accepted 120 in 1874 and (b) the isolation of germanium by Winkler in 1886. (shrink)
The history of the classification of chemical elements is reviewed from the point of view of a bibliophile. The influence that relevant books had on the development of the periodic table and, conversely, how it was incorporated into textbooks, treatises and literary works, with an emphasis on the Spanish bibliography are analyzed in this paper. The reader will also find unexpected connections of the periodic table with the Bible or the architect Buckminster Fuller.
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)
In this paper, domain-specificity is presented as an understudied problem in chemical education. This argument is unpacked by drawing from two bodies of literature: learning of science and epistemology of science, both themes that have cognitive as well as philosophical undertones. The wider context is students’ engagement in scientific inquiry, an important goal for science education and one that has not been well executed in everyday classrooms. The focus on science learning illustrates the role of domain specificity in scientific reasoning. (...) The discussion on epistemology of science presents ideas from the emerging field of philosophy of chemistry to highlight the much neglected area of epistemology in chemical education. Domain-specificity is exemplified in the context of chemical laws, in particular the Periodic Law. The applications of the discussion for chemical education are explored in relation to argumentation, itself an epistemologically grounded discourse pattern in science. The overall implications include the need for reconceptualization of the nature of teaching and learning in chemistry to include more particular epistemological aspects of chemistry. (shrink)
The discovery of the noble gases and their incorporation into the periodic system are examined in this paper. A chronology of experimental reports on argon and helium and the properties relevant to their nature and position in the periodic system is presented. Proposals on the nature of argon and helium that appeared in the aftermath of their discovery are examined in light of the various empirical and theoretical considerations that supported and contradicted them. ``The piece that would not fit'' refers (...) not only to argon, the element that at first seemed not to fit into the periodic system, but also to the piece or pieces of evidence that various researchers and observers were prepared to discard or discount in coming to terms with the newly discovered gases. (shrink)
The six platinum group metals (pgms: ruthenium, rhodium, palladium, osmium, iridium and platinum) posed a number of problems for 19th-century chemists, including Mendeleev, for their Periodic classification. This account discusses the discovery of the pgms, the determination of their atomic weights and their classification.
While most chemists agree on what is a metal and what is a non-metal there is a disagreement with respect to what is a metalloid and what is a transition metal. It is believed that this problem can be solved if two new terms are adopted: typical and less typical metals. These new terms will also help reconcile the European Periodic Table versus the North American regarding numbering of groups as well as the IUPAC numbering which could be as well (...) abandoned in favour of group names as will be shown in the manuscript. (shrink)
Chemistry and physics are two sciences that are hard to connect. Yet there is significant overlap in their aims, methods, and theoretical approaches. In this book, the reduction of chemistry to physics is defended from the viewpoint of a naturalised Nagelian reduction, which is based on a close reading of Nagel's original text. This naturalised notion of reduction is capable of characterising the inter-theory relationships between theories of chemistry and theories of physics. The reconsideration of reduction also leads to a (...) new characterisation of chemical theories. This book is primarily aimed at philosophers of chemistry and chemists with an interest in philosophy, but is also of interest to the general philosopher of science. (shrink)
This paper addresses the conceptual as well as social origins of Mendeleev’s discovery of the periodic law and its reception by the chemical community by taking account of three factors: Mendeleev’s early research and its relevance to the discovery; his concepts of chemistry, especially that of the chemical elements; and the social context of the discovery and the reception in the chemical community. Mendeleev's clear distinction between abstract elements and simple bodies was a departure from Lavoisier’s famous definition of elements (...) as an endpoint of analysis and originated from his research in indefinite compounds. As a comparison, the paper also analyzes Lothar Meyer’s approach to the classification of the elements. Mendeleev’s new concept of chemical elements and the existence of an audience in the form of the newly established Russian Chemical Society, and his ``German connection'', helped Mendeleev in his discovery and its reception. (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)
Attempts to explain the periodic system as a manifestation of regularities in the structure of the atoms of the elements are as old as the system itself. The paper analyses some of the most important of these attempts, in particular such works that are historically connected with the recognition of the electron as a fundamental building block of all matter. The history of the periodic system, the discovery of the electron, and ideas of early atomic structure are closely interwoven and (...) transcend the physics–chemistry boundary. It is pointed out that J. J. Thomson's discovery of the electron in 1897 included a first version of his electron atomic model and that it was used to suggest how the periodic system could be understood microphysically. Thomson's theory did not hold what it promised, but elements of it were included in Niels Bohr's first atomic model. In both cases, Thomson's and Bohr's, the periodic system played an important role, heuristically as well as justificatory. (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.
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 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)
This paper explores the development of the chemical table as a tool designed for chemical information visualization. It uses a historical context to investigate the purpose of chemical tables and charts, analyzing them from the perspective of theory of tables, cartography, and design. It suggests reasons why the two-dimensional periodic table remains the de facto standard for chemical information display.
This is a periodic table explicitly for chemists rather than physicists. It is derived from Newlands’ columns. It solves many problems such as the positions of hydrogen, helium, beryllium, zinc and the lanthanoids but all within a succinct format.
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)
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)
The Periodic Table has the column of the noble gas atoms (He, Ne, Ar, Kr, Xe, Rn) as one of its main pillars. Indeed the inert chemical nature of their closed shell structure is so striking that it is sometimes extended to all such structures. Is it true however that any closed shell, say a closed d-subshell will denote a lack of chemical activity? Take the noble metals for instance, so renowned for their catalytic capacity. Platinum has 10 electrons in (...) its valence shell which makes one of its excited states to be a closed 5d10–6s0 state. Surely this state would not be expected to be crucial to the catalytic activity of platinum, or would it? Or take palladium whose ground state is precisely the 4d10–5s0 state, should we expect that an isolated Pd atom at near zero-point temperature would attack a closed-shell hydrogen molecule efficiently? We shall here show that this is precisely the case; the closed-shell excited states of nickel and platinum are indeed crucial, through symmetry avoided crossings, for their reactivity. Other valuable catalysts as ruthenium depend on their excited states with maximal d-shell occupancy for their activity. The most notable confirmation of this new finding; that closed d-shells are vital to the catalytic activity of noble metals however, is the case of palladium whose closed-shell ground state is indeed capable of attacking hydrogen and hydrocarbon molecules even at temperatures well below 10 K as was predicted theoretically and immediately confirmed experimentally. (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.
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)
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 early Periodic Tables displayed an 8-Group system. Though we now use an 18-Group array, the old versions were based on evidence of similarities between what we now label as Group (n) and the corresponding Group (n + 10). As part of a series on patterns in the Periodic Table, in this contribution, these similarities are explored for the first time in a systematic manner. Pourbaix (Eh–pH) diagrams have been found particularly useful in this context.
As part of a series of contributions on patterns in the periodic table, the relationships among the transition metals are examined here in a systematic manner. It is concluded that the traditional method of categorizing transition elements by group or by period is not as valid as by using combinations thereof. From chemical similarities, it is proposed that the transition metals be considered as the [V–Cr–Mn] triad; the [Fe–Co–Ni–Cu] tetrad; the [Ti–Zr–Hf–Nb–Ta] pentad; the [Mo–W–Tc–Re] tetrad; and the [Ru–Os–Rh–Ir–Pd–Pt–Au] heptad. Silver (...) does not fit neatly in anywhere and is better linked with thallium. (shrink)
The usefulness of isoelectronic series (same number of total electrons and atoms and of valence electrons) across Periods is often overlooked. Here we show the ubiquitousness of isoelectronic sets by means of matrices, arrays, and sequential series. Some of these series have not previously been identified. In addition, we recommend the use of the term valence-isoelectronic for species which differ in the number of core electrons and pseudo-isoelectronic for matching (n) and (n + 10) species.
Similarities in properties among pairs of metallic elements and their compounds in the lower-right quadrant of the Periodic Table have been named the ‘Knight’s Move’ relationship. Here, we have undertaken a systematic study of the only two ‘double-pairs’ of ‘Knight’s Move’ elements within this region: copper-indium/indium-bismuth and zinc-tin/tin-polonium, focussing on: metal melting points; formulas and properties of compounds; and melting points of halides and chalcogenides. On the basis of these comparisons, we conclude that the systematic evidence for ‘Knight’s Move’ relationships (...) derives from similarities in formulas and properties of matching pairs of compounds in the same oxidation state. Physical properties, such as melting points, do not provide consistent patterns and trends and hence should not be considered as a common characteristic of this relationship. (shrink)
We review different studies of the Periodic Law and the set of chemical elements from a mathematical point of view. This discussion covers the first attempts made in the 19th century up to the present day. Mathematics employed to study the periodic system includes number theory, information theory, order theory, set theory and topology. Each theory used shows that it is possible to provide the Periodic Law with a mathematical structure. We also show that it is possible to study the (...) chemical elements taking advantage of their phenomenological properties, and that it is not always necessary to reduce the concept of chemical elements to the quantum atomic concept to be able to find interpretations for the Periodic Law. Finally, a connection is noted between the lengths of the periods of the Periodic Law and the philosophical Pythagorean doctrine. (shrink)
The placement of hydrogen in the periodic table has unique implications for fundamental questions of chemical behavior. Recent arguments in favor of placing hydrogen either separately at the top of the table or as a member of the carbon family are shown to have serious defects. A Coulombic model, in which all compounds of hydrogen are treated as hydrides, places hydrogen exclusively as the first member of the halogen family and forms the basis for reconsideration of fundamental concepts in bonding (...) and structures. The model provides excellent descriptive and predictive ability for structures and reactivities of a wide range of substances. (shrink)
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)
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 purpose of this paper is to propose a new design for the presentation of the periodic system of the elements. It is a system that highlights the fundamental importance of elements as basic substances rather than elements as simple substances. Furthermore the fundamental nature of atomic number triads of elements is put to use in obtaining a new perfect triad by relocating hydrogen among the halogens to give the triad H, F, Cl. An unexpected regularity in the period lengths (...) of successive rows is obtained on rearranging the table to start with the halogens on the left-hand side. The relative virtues of this table, as compared with the medium-long form and the left-step table, are discussed. (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)
This commentary provides a critical examination of a recent article by Allen and Knight in which the authors claim to provide the long-sought explanation for the Madelung, or n + ℓ, n rule for the order of orbital filling in many-electron atoms. It is concluded that the explanation is inadequate for several reasons.