It is not often realized by chemists that the special theory of relativity is behind several aspects of quantum chemistry. The Schrdinger equation itself is based on relations between space-time and energy-momentum four vectors. Electron spin is, of course, the most obvious manifestation of relativity. The chemistry of some heavy elements is…

A simple experiment concerning the elasticity of wood is described that can easily be performed at home. The forces needed to produce a stress in wood are measured and compared. Provides a mathematical discussion of the elasticity and stress of wood. (MVL)

Using Fourier transformation methods in nuclear resonance has made possible increased sensitivity in chemical analysis. This article describes data acquisition, data processing, and the frequency spectrum as they relate to this technique. (CW)

Nuclear magnetic resonance and infrared are two spectroscopic methods that commonly use the Fourier transform technique. Discussed are the similarities and differences in the use of the Fourier transform in these two spectroscopic techniques. (CW)

Discussed are the mechanisms of nuclear magnetic relaxation, and applications of relaxation times. The measurement of spin-lattice relaxations is reviewed. It is stressed that sophisticated techniques such as these are becoming more important to the working chemist. (CW)

Described is an experiment which illustrates valence isomerization, the trapping of a reactive intermediate and retrosynthetic analysis applied to the Diels-Alder reaction. Included is a background discussion, experimental procedures, and a discussion of the analysis. (CW)

Describes three microcomputer programs that allow geology students to deform two-dimensional images on a computer screen and then to measure changes in angular relationships. Two of the programs simulate pure and simple shear and the third simulates variations in shear strain that occur in shear zones. (ML)

The apparatus, reagents, preliminary classification, nomenclature, acquisition, and procedures used in the identification of synthetic polymers are described. Specific tests for the identification of the presence of hydrocarbons, chlorine, fluorine, sulfur, and nitrogen and the absence of halogens and sulfur are discussed. (CW)

Presented is a teaching progression that enhances learning through low-cost, manipulative transparencies. Discussed is instruction about restriction enzymes, plasmids, cutting plasmids, plasmid maps, recording data, and mapping restriction sites. Mapping wheels for student use is included. (CW)

Describes an experiment in which stretching a rubber band can be used to compare the statistical theory of rubber elasticity with its continuum mechanics counterpart. Employs the use of the equation of the state of rubber elasticity and the Mooney-Rivlin equation. (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 a physical chemistry experiment which uses spectroscopy to measure the heat of formation of Na2SiF6. Discusses the opportunities for students to see the use of a familiar instrument in an unfamiliar application, emphasizing that there are often many ways to attack problems in science. (TW)