This article describes how data are used to analyze the pattern of ionization energies of the lanthanide elements. Different observed pathways of ionization between different ground states are discussed, and the effects of pairing, exchange, and orbital interactions on ionization energies of the lanthanides are evaluated. When all the above…

This article describes the use of Latin-derived words and terms used in chemistry, and explores the meaning of these words, so as to lead to a better understanding of these words, so commonly used in the teaching of chemistry. As the article shows, there are many such words, and with some elementary knowledge, a greater meaning is given to these…

This interview provides glimpses of Joseph J. Lagowski and his life from the time he played with a Gilbert chemistry set, to his tenure at The University of Texas at Austin. His initial interest in chemistry was further nurtured and developed thanks to an excellent high school teacher. In the interview, Lagowski discusses his research in…

Research and literature on the adoption of technology provides a useful lens through which to view the adoption and implementation of classroom response systems (CRS). The technology adoption life cycle describes groups of adopters in ways that are helpful in understanding the adoption and sustained implementation of CRS in chemistry departments.…

Two complementary techniques to gauge student understanding and inspire interactive learning in the chemistry classroom are presented. Specifically, this article explores the use of student responses with their thumbs as an alternative to electronic-response systems and complementing these experiences with longer, task-based questions in an…

Any student is expected to know that correct prediction is a necessary, but not a sufficient, condition any theory must meet to be acceptable. However, an eventual weakening of reflective and critical attitudes when dealing with "whats" and "whys" in science learning can easily lead to an identification of the predictive success of a given…

This classroom activity connection demonstrates the differences between the effects of NaCl (a salt of monovalent metal ions) and CaCl[subscript 2] (a salt of polyvalent metal ions) on swollen superabsorbent polymer gels. Being ionic compounds, NaCl and CaCl[subscript 2] both collapse the swollen polymer gels. The gel contracted by NaCl reswells…

This quick and inexpensive demonstration of the salting of an alcohol out of an aqueous solution illustrates the impact of intermolecular forces on solubility using materials familiar to many students. Ammonium sulfate (fertilizer) is added to an aqueous 35% solution of isopropyl alcohol (rubbing alcohol and water) containing food coloring as a…

We describe how we use boiling-point trends of group IV-VII hydrides to introduce intermolecular forces in our first-year general chemistry classes. Starting with the idea that molecules in the liquid state are held together by some kind of force that must be overcome for boiling to take place, students use data analysis and critical reasoning to…

To help in interpreting the polarity of a molecule, charge separation can be visualized by mapping the electrostatic potential at the van der Waals surface using a color gradient or by indicating positive and negative regions of the electrostatic potential using different colored isosurfaces. Although these visualizations capture the molecular…

The near-UV spectrum of benzene is used to illustrate the effects of variations in instrument spectral bandwidth on absorbance and molar absorptivity measurements and on the independence of values of quantities such as the oscillator strength that are based on integrated absorptivity. Excel-based computer simulations are provided that help develop…

A new free graphical teaching tool that highlights the beautiful organic architectures of the top selling pharmaceuticals is detailed on two posters. In addition to the multitude of teaching and data-mining opportunities these posters offer, they were also created to emphasize the central role organic chemists play in the development of new…

An in-class molecular modeling exercise is described. Groups of students are given molecular models to investigate and questions about the models to answer. This exercise is a quick and effective way to review nomenclature, stereochemistry, and conformational analysis.

A variety of approaches to the concept of oxidation and reduction appear in organic textbooks. The method proposed here is different than most published approaches. The oxidation state is calculated by totaling the number of heterogeneous atoms, [pi]-bonds, and rings. A comparison of the oxidation states of reactant and product determine what type…

A vast majority of polar additions of Bronsted acids to alkynes involve a termolecular transition state. With strong acids, considerable positive charge is developed on carbon and Markovnikov addition predominates. In less acidic solutions, however, the reaction is much slower and the transition state more closely resembles the olefinic product.…