Catt's anomaly is a sort of "thought experiment" (a "gedankenexperiment") where electrons seem to travel at the speed of light. Although its author argued with conviction for many years, it has a clear and satisfactory solution and it can be considered indubitably just an apparent paradox. Nevertheless, it is curious and…

In this paper the mechanical properties of carbon nanotubes are discussed in connection with the possibility to use them for the construction of a space elevator. From the fundamental information about the structure of a carbon nanotube and the chemical bond between carbon atoms, Young's modulus and the ultimate tensile strength are…

The Wittig reaction is one of the most useful reactions in organic chemistry. Despite its prominence early in the organic chemistry curriculum, the exact mechanism of this reaction is still under debate, and this controversy is often neglected in the classroom. Introducing a simple computational study of the Wittig reaction illustrates the…

Why is chemistry so difficult? A seminal paper by Johnstone (1982) offered an explanation for why science in general, and chemistry in particular, is so difficult to learn. He proposed that an expert in chemistry thinks at three levels; the macro (referred to as the observational level in this article), the sub-micro (referred to as the molecular…

An experiment is described that determines the activation energy (E[subscript a]) of the iodide-catalyzed decomposition reaction of hydrogen peroxide in a much more efficient manner than previously reported in the literature. Hydrogen peroxide, spontaneously or with a catalyst, decomposes to oxygen and water. Because the decomposition reaction is…

Charges and fields in a straight, infinite, cylindrical wire carrying a steady current are determined in the rest frames of ions and electrons, starting from the standard assumption that the net charge per unit length is zero in the lattice frame and taking into account a self-induced pinch effect. The analysis presented illustrates the mutual…

Raman spectroscopy is a powerful experimental technique, yet it is often missing from the undergraduate physical chemistry laboratory curriculum. Tetrachloromethane (CCl[subscript 4]) is the ideal molecule for an introductory vibrational spectroscopy experiment and the symmetric stretch vibration contains fine structure due to isotopic variations…

The molecular basis of evolution is an important and challenging concept for students to understand. In a previous article, we provided some of the scientific background necessary to teach this topic. This article features a series of laboratory activities demonstrating that molecular events can alter the genomes of organisms. These activities are…

A unique homework assignment has been designed as a review exercise to be implemented near the end of the one-year undergraduate organic chemistry sequence. Within the framework of the exercise, students derive potential mechanisms for glucose ring opening in the aqueous mutarotation process. In this endeavor, 21 general review principles are…

Both, virtual and printed 3D crystal models can help students and teachers deal with chemical education topics such as symmetry and point groups. In the present paper, two freely downloadable tools (interactive PDF files and a mobile app) are presented as examples of the application of 3D design to study point-symmetry. The use of 3D printing to…

The advantages of Gaussian-type orbitals (GTO) over Slater-type orbitals (STO) in quantum chemistry calculations are clarified here by means of a holistic approach. The popular Microsoft Office Excel program was used to create an interactive application with which students are able to explore the features of GTO, including automatic calculations…

The hydrogenation of alkenes by heterogeneous catalysts has been studied for 80 years. The foundational mechanism was proposed by Horiuti and Polanyi in 1934 and consists of three steps: (i) alkene adsorption on the surface of the hydrogenated metal catalyst, (ii) hydrogen migration to the beta-carbon of the alkene with formation of a delta-bond…

Our previous work correlated bond angles of group V and group VI hydrides (AH[subscript 3]E and AH[subscript 2]E[subscript 2], respectively, where E represents a lone electron pair) to the electronegativities of the atoms using the fraction of s character to relate the two. Here we have extended the correlation to the AH[subscript 2]X[subscript 2]…

Probably owing to the prejudice that gold is a metal too noble to be used much in chemistry, the chemistry of this element has developed much later than that of its congeners and neighbors in the periodic table. In fact, before and after the time of alchemists, and up to the 20th century, all chemistry of gold was mainly performed in attempts to…

We propose an in silico experiment to introduce the classical density functional theory (cDFT). Density functional theories, whether quantum or classical, rely on abstract concepts that are nonintuitive; however, they are at the heart of powerful tools and active fields of research in both physics and chemistry. They led to the 1998 Nobel Prize in…