In the last decade, the notion of triad was reintroduced by Eric Scerri, who suggested it as a possible categorical criterion to represent chemical periodicity. In particular, he reformulated the notion of triad in terms of atomic number instead of atomic weights; in this way, the value of the intermediate term of the triad became the exact average of the values of the two extremes. Following the inspiration of Scerri’s work, the main purpose of this article is to obtain a (...) representation where all the relations among the chemical elements that form the groups of the periodic system can be reconstructed on the basis of triads, without using electronic configurations. (shrink)

A lively philosophical debate has lately arisen over the nature of elementhood in chemistry. Two different senses in which the technical term ELEMENT is currently in use by chemists have been identified, leaving chemistry open to the logical fallacy of equivocation. This paper introduces a third, more elemental candidate: the high-enthalpy short-lived unbonded atom. An enthalpy index based on free-atoms-as-elements is established, whereby one can monitor the degree to which an atom’s spin-based attractive force is implemented exo-enthalpically when the atom (...) binds chemically to others. Enthalpy indexing shows that the strength of an atom’s attractive force is proportional to its spin angular momentum. Vibrational spectroscopy shows that the force varies inversely as the fourth power of the inter-atom distance. Both features differentiate the chemical force from the stronger electromagnetic force and from the weaker Van der Waals force. (shrink)

Immanuel Kant has built up a dualistic epistemology that seems to fit to the peculiarities of chemistry quite well. Friedrich Paneth used Kant’s concept and characterised simple and basic substances which refer to the empirical and to the transcendental world, respectively. This paper takes account of the Kantian influences in Paneth’s philosophy of chemistry, and discusses pertinent topics, like observables, atomism and realism.

This note is intended to address one particular issue in the relative status of Quantum Chemistry in comparison to both Chemistry and Physics. It has been suggested, in the context of the question of the reduction relations between Chemistry and Physics that Quantum Chemistry as a research programme is incapable of furnishing useful guidance to practising chemists. If true, this claim will let us qualify Quantum Chemistry as a degenerating research programme, which, due to its complexity has difficulty to be (...) applied to Chemistry. This claim is shown to be false. The replacement claim I wish to make is that Quantum Chemistry is perfectly capable of furnishing such guidance, but renders the ontological status of many models favored by chemists problematic. Quantum Chemistry, however, validates these models in an instrumental fashion. I will argue that Quantum Chemistry is a progressive research programme. (shrink)

This paper analyzes views of the Stoic philosopher Posidonius (1st century BC) in the light of modern Chemistry. I propose that Posidonius’ account on “generation and destruction” bears noteworthy similarities to the scientific notions of chemical elements, chemical species, nuclear reactions, and the law of conservation of mass. I find that his views compare favorably also with our understanding of chemical change at solid surfaces. Provided his thought is correctly placed in the cultural context of his day, I argue that (...) Posidonius deserves a previously un-acknowledged consideration in the historical background of modern Chemistry. (shrink)

The analysis of the concept of orbital allows us to argue that—in opposition to a recent position in philosophy of science—it is impossible to defend the autonomy of the chemical reality in regard to physical reality, appealing to the idea that there is a conceptual rupture among a chemical interpretation and a quantuminterpretation of the concept. This is the case because there are not two different interpretations of the concept of orbital. On the contrary, the concept involved in structural chemistry (...) and in quantum chemistry comes from quantum mechanics.El análisis del concepto de orbital permite argumentar—en oposición a una propuesta reciente en filosofía de la química—que no es posible defender la autonomía ontológica de la realidad química respecto de la física, sobre la base de una ruptura conceptual entre una interpretación química del concepto y otra propia de la mecánica cuántica. Esto es así porque no existen tales interpretaciones distintas del concepto de orbital, sino que, por el contrario, este concepto en química cuántica y en química estructural proviene de la mecánica cuántica. (shrink)

Robin Hendry has recently argued that although the term ‘element’ has traditionally been used in two different senses, there has nonetheless been a continuity of reference. The present article examines this author’s historical and philosophical claims and suggests that he has misdiagnosed the situation in several respects. In particular it is claimed that Hendry’s arguments for the nature of one particular element, oxygen, do not generalize to all elements as he implies. The second main objection is to Hendry’s view that (...) the qua problem can be illuminated by appeal to the intention of scientists.Keywords: Element; Simple substance; Basic substance; Antoine Lavoisier; Dmitri Mendeleev; Reference; Qua problem. (shrink)

The function of metaphor in science has been labeled as decorative, persuasive, heuristic, instrumental, facilitating or obstructing. It has sometimes been regarded as inspiring, provoking, perverting or destroying rational thought. Metaphor’s positive role has been noted by philosophers, historians of chemistry, and science education researchers. It has been hailed as a descriptive and explanatory device that stimulates and shapes concept development. I discuss how metaphor functions in science generally, then refine this idea through an examination metaphor’s role in chemical thinking (...) in three contexts: the history and philosophy of chemistry, laboratory research practice, and chemical education. I aim to show how metaphor is already operative in the chemist’s use of the concept of chemical element and that this understanding characterizes chemical thinking in general. The chapter concludes with a discussion of a specifically chemical understanding of metaphor. (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)

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)

From the perspective of successive events, chemical reactions are expressed or thought about, in terms of the cause-effect category. In this work, I will firstly discuss some aspects of causation and interaction in chemistry, argue for the interaction, and propose an alternative or complementary representation scheme called “interaction diagram”, that allows representing chemical reactions through a geometric diagram. The understanding of this diagram facilitates the analysis of reactions in terms of the interaction, or reciprocal action, among the participating entities. Secondly, (...) I will describe the model and provide examples and finally, I will discuss the scope and limitations of the current development status of the model. (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)

The autonomy of chemistry and the legitimacy of the philosophy of chemistry are usually discussed in the context of the issue of reduction of chemistry to physics, and defended making use of the failure of reductionistic claims. Until quite recent times a rather widespread viewpoint was, however, that the failure of reductionistic claims concerns actually epistemological aspect of reduction only, but the ontological reduction of chemistry to physics cannot be denied. The new problems of the autonomy of chemistry in the (...) context of reductionism seem to be ontological and metaphysical. In the present paper it is argued that there is no need for some kind of metaphysical-ontological underpinning for rejection of the secondary positions of chemistry and philosophy of chemistry with respect to physics and philosophy of physics. The issue can be elucidated in terms of the philosophy of science accepting practical realism (also known by other names). (shrink)

Friedrich Paneth’s conception of “chemical element” has functioned as the official definition adopted by the International Union of Pure and Applied Chemistry since 1923. Paneth maintains a distinction between empirical and “transcendental” concepts of element; furthermore, chemical science requires fluctuation between the two. The origin of the empirical-transcendental split is found in Immanuel Kant’s classic Critique of Pure Reason (1781/1787). The present paper examines Paneth’s foundational concept of element in light of Kant’s attempt, late in life, to revoke key distinctions (...) made in his Critique, including that of regulative and constitutive functions of reason. In a section of his Opus postumum devoted to the “Transition from the Metaphysical Foundations of Natural Science to Physics,” Kant bends his philosophical system to address the newly emerging sciences of matter of his time. Specifically, he tried, without success, to develop the transcendental ground for microscale motions of bodies encountered in physical, electrical and chemical processes. Paneth’s discussion of chemical element does not take the Opus postumum into account, which is why it begins with a rejection of Kant’s rejection (in his earlier writings) of chemistry’s status as science. I make the case that Paneth’s definition of element effectively maintains something very like Kant’s critical separation of regulative and constitutive principles, while a advancing the concept of chemical science. (shrink)

In this paper, I explore a seldom-recognized connection between the ontology of abstract objects and a current issue in the philosophy of chemistry. Specifically, I argue that realism with regard to universals implies a view of chemical elements similar to F.A. Paneth’s thesis about the dual nature of the concept of element.

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)