Contrasted are DNA viruses, RNA viruses, and RNA retroviruses. The structure, genome, and replication of retroviruses are discussed. The discovery, structure, and action of the HIV virus are described. A list of 17 references is included. (CW)

Focuses on the CAS ONLINE database, the Registry File which consists of substance names, Registry numbers and characteristics, and actual structural representations. Presents several examples covering most typical problems a chemist faces daily. (Author/MVL)

Uses simple pulse NMR experiments to discuss Fourier transforms. Studies the generation of spin echoes used in the imaging procedure. Shows that pulse NMR experiments give signals that are additions of sinusoids of differing amplitudes, frequencies, and phases. (MVL)

Investigates ground state electron configurations for some common elements using graphical methods. Bases observed tendencies on following ideas: "occupancy of differing shells, occupancy of differing subshells within a given shell, double occupancy vs. single occupancy of an orbital, and quantum-mechanical exchange." (ML)

The "Central Dogma" of genetics states that one gene, located in a DNA molecule, is ultimately translated into one protein. As important as this idea is, many teachers shy away from teaching the actual mechanism of gene translation, and many students find the concepts abstract and inaccessible. This article describes a unit, called Genetics…

The effect of intervening use of molecular visualization software was tested on 73 first-year general chemistry students. Pretests and posttests included both traditional multiple-choice questions and model-building activities. Overall students improved after working with the software, although students performed less well on the model-building…

Kinetic models of a gas can be hard for students to understand. Typical tools do not display events at the microscopic level, yet computer simulations of the molecules lack a hands-on aspect. Here a new tool is described that combines the squeezing of a syringe with a computer simulation, and it is shown that this has worked well in class for both…

Describes several techniques to help students visualize the principles of polymer chemistry. Outlines demonstrations using simple materials (such as pop-it beads, thread, and wire) to illustrate the size of macromolecules, the composition of copolymers, and the concept of molecular mass. (TW)

Discusses the teaching of electron configurations and various systems used to help students write them correctly. Presents an approach to this type of instruction which uses diagrams and mnemonic devices. Examples of exercises which encourage the use of this method are provided. (TW)

Describes a procedure for constructing point groups based on the symmetric parent molecules of methane and adamantane. Intended for use in teaching concepts such as subgroups and cosets to beginners in group theory. (TW)

Describes phase transition in solids and shows how soap films can be used to demonstrate this phenomenon. (Author/SK)

Reviews the basis for the technique and its experimental requirements. Describes a few examples of the analytical problems to which surface-enhanced Raman spectroscopy (SERS) has been and can be applied. Provides a perspective on the current limitations and frontiers in developing SERS as an analytical technique. (MVL)

Presents the mechanistic ideas underlying reactions between nucleophiles and carbonyl compounds as well as some popular misconceptions. Relates reactions of carboxylic acid derivatives to those of aldehydes and ketones. Discusses leaving group ability and the ability of carbonyl oxygen to accept a negative charge. (Author/MVL)

Reexamines the electronic structure of water considering divergent views. Discusses several aspects of molecular orbital theory using spectroscopic molecular orbitals and localized molecular orbitals. Gives examples for determining lowest energy spectroscopic orbitals. (ML)

Describes why specific forms of orbitals used to interpret spectroscopy involving electronic transitions may not say much about the electronic structure of molecules. Discusses several theoretical approaches to explain the anomoly. Determines that the Lewis electron-pair model for molecules is a good predictor of spectroscopic results. (ML)