Foundations of Chemistry最新文献

Eric Scerri is the world-leading expert on (the history of) Periodic Table and was quite recently named the second-most influential academic in the field of chemistry over the last decade by Academic Influence. In this interview we discuss his main questions of interest in the philosophy of chemistry—the question of reduction of chemistry to physics and the dual sense of chemical element—in the context of his main study object, the periodic table of elements. Among other things, we touch upon the more specific issues related to chemical classification, such as pair reversal, the placement and order of certain elements, the structure and shape of periodic table, etc. We also discuss the status of chemical kinds as a traditional epitome of ‘natural kinds’, the relevance of philosophy of chemistry for chemical science, the implications of ‘turn to practice’ for philosophy of chemistry, and many other issues. Finally, Eric Scerri also discusses his most recent book, ‘What is a Chemical Element?’, co-edited with Elena Ghibaudi and published by Oxford University Press in 2020.

It is a notion commonly acknowledged that in his work Timaeus the Athenian philosopher Plato (c. 429–347 BC) laid down an early chemical theory of the creation, structure and phenomena of the universe. There is much truth in this acknowledgement because Plato’s “chemistry” gives a description of the material world in mathematical terms, an approach that marks an outstanding advancement over cosmologic doctrines put forward by his predecessors, and which was very influential on western culture for many centuries. In the present article, I discuss inter-transformations among Plato’s four types (fire, air, water, and earth) as well as the interpretation they received in the literature. I find that scientists and scholars generally emphasized (and often misunderstood) mathematical aspects of these “reactions” over the philosophical ones. I argue that Plato’s “chemistry” in fact bears on crucial topics of his philosophical system, such as Forms, Becoming, causation and teleology. I propose that consideration of these doctrines help to understand not only the sense of his “chemical” reactions, but also the reason why their stoichiometry is by surface balance and is restricted only to types that come to be and pass away but not to those that provoke the inter-transformations.

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 (specially the 32-column left-step Table), discuss potential advantages and answer to some criticisms on them.

The concept of substance is considered fundamental in order to understand chemistry and other related concepts, but many problems have been reported about its learning process. Considering the importance of textbooks in the training of chemistry teachers, this study aimed to identify the concepts of substance in general chemistry textbook glossaries. In addition, the study assessed the concepts of substance in relation to other chemical concepts and, when available, compared them with the concepts established by the IUPAC (Compendium of chemical terminology, 2 ed. Blackwell Scientific Publications, Oxford, 1997). The methodology employed was content analysis and the results showed that concepts and statements related to the term ‘substance’ are different in the general chemistry textbooks analyzed. They also differ from those stated by IUPAC. Furthermore, it was found that many concepts are dependent on the concept of substance. It is concluded that there must be a greater effort from the community of chemists and the teaching of chemistry in the search for conceptual uniformity to reduce the problems of conceptual understanding.

Teaching chemistry remains a profoundly challenging activity. This paper arises from reflection on the challenges of creating meaningful assessments. Herein a simple framework to assist in making more visible the different kinds of knowledge required for mastery of chemistry is described. Building from a realist foundation the purpose of this paper is to lay the intellectual scaffolding for the framework. By situating the framework theoretically, it is intended to highlight the value of engaging with philosophy for the project of knowledge building in chemistry. Use of this framework has laid bare some significant limitations to the ways in which organic chemistry has been assessed. Making the visible to students aids in their engagement with knowledge and for a small minority has developed their understanding of science more generally. The framework provides a simple, easily usable tool for the evaluation of chemistry assessments.

I respond to Scerri’s recent reply to my claim that there was a scientific revolution in chemistry in the early twentieth Century. I grant, as Scerri insists, that there are significant continuities through the change about which we are arguing. That is so in all scientific revolutions. But I argue that the changes were such that they constitute a Kuhnian revolution, not in the classic sense of The Structure of Scientific Revolutions, but in the sense of Kuhn’s mature theory, developed in the 1980s and early 1990s.

This manuscript explores the orthogonality constraints on configurations and orbitals subject to the property that states are mutually orthogonal. The orthogonality constraints lead to properties that affect the description of chemical systems. When states are described as linear combinations of (orthogonal or non-orthogonal) configurations, the coefficient matrix (mapping configurations to states) diagonalises S⁻¹H. Therefore, single-configuration states are only possible in one-electron systems: non-orthogonal configurations yield single-configuration states only if S⁻¹H is diagonal, but this would violate the orthonormalisation constraint. Further, the coefficient matrix is not constrained to be square (the number of configurations may differ from the number of configurations). Similarly, the orbitals used to construct configurations may also be orthogonal or non-orthogonal; orbitals are only required to be mutually orthogonal at the one-electron limit. Orthogonal orbitals are generally preferred due to their mathematical and conceptual simplicity, leading to fictitious unoccupied orbitals. Since the Fock operator is orthogonality agnostic, non-orthogonal (occupied) orbitals can be generated by solving the Fock equation independently for each electron; the virtual orbitals produced by this conception are true excitation orbitals as they are eigensolutions of the Fock operator. Additionally, we show that the number of molecular orbitals generated is not restricted to the number of atomic orbitals (or basis functions) employed in the computation. This manuscript explores the mathematical relationships that need to be satisfied under the various orthogonality regimes. We also present mathematical relationships that provide results that are independent of the orthogonality approximation within a particular computational method.

We review the early works which were precursors of the Conceptual Density Functional Theory. Starting from Thomas–Fermi approximation and from the exact formulation of Density Functional Theory by Hohenberg and Kohn’s theorem, we will introduce electronegativity and the theory of hard and soft acids and bases. We will also present a general introduction to the Fukui functions, and their relation with nucleophilicity and electrophilicity, with an emphasis towards the importance of these concepts for chemical reactivity.

We re-examine the history of the element “nipponium” discovered by a Japanese chemist Masataka Ogawa in 1908. Since 1996 H.K. Yoshihara has made extensive research into Ogawa’s work and revealed evidence that nipponium proposed for the place of the atomic number of 43 was actually rhenium (75). In this paper, we provide critical re-interpretations of the existing information and confirmed that Ogawa left indisputable evidence that nipponium was in fact rhenium. We further discuss the reasons for the existing doubts and criticism against Ogawa’s discovery and Yoshihara’s interpretation, and attempt to resolve them.