Discusses various interpretations of the concept of chemical valence and describes a method for correlating bond length with valence. (MLH)

Describes ways that students can construct molecular models from fishing-tackle materials. (MLH)

Describes an inexpensive, easily constructed model of the right-handed alpha-helix, consisting of cardboard, plastic tubing and a wooden support. (MLH)

Describes an inexpensive double-beam laser photometry experiment to determine the molar heat of sublimation of I-2. The experiment employs common laboratory materials and components and gives results with a two percent to three percent accuracy. (Author/GA)

Describes how the color of an object is related to its chemical structure. (CP)

Describes the bonding tendencies of the borabenzene anion and its transition metal complexes. (CP)

Provides an empirical analysis of the specificity and efficiency of reactions based on the Hard and Soft Acids and Bases (HSAB) principle. (Author/CP)

Discusses the relation between amino acids and ribonucleic acid (RNA) in a copolymer. (HM)

Describes a practical and visual way of extending the concept of symmetry present in nature to the quantum structure of molecules. (SL)

Provides a theoretical model of the deoxyribonucleic acid (DNA) helix-to-coil transition in order to obtain magnitude information about the strength of the molecular bonds involved. (Author/CP)

Describes the origins, definitions, tools, and principles of host-guest chemistry. Gives examples of chiral recognition in complexation, of partial transacylase mimics, of caviplexes, and of a synthetic molecular cell. (Author/RT)

Describes a simple way of obtaining a set of relative intensities of spin-spin splitting lines using Pascal's triangle rather than calculating binomial coefficients. Provides tables showing Pascal's triangle and the relative intensities of multiplets for a range of nuclear spins. (TW)

Provided is a review of a chemical software package. The package makes possible an instructional technique that is not effective by any other means, namely the ability to view molecular shapes in three dimensions. The program can be used with either IBM or Apple hardware. (RH)

Discusses: (l) molybdoenzymes (examining their distribution and metabolic role, composition and redox strategy, cofactors, substrate reactions, and mechanistic possibilities); (2) structural information on molybdenum (Mo) centers; (3) modeling studies (Mo-co models, nitrogenase models, and the MO-S duo); and (4) the copper-molybdenum antagonism.…