Discusses the difficulties that some students have in understanding the concept of chemical reactions. Proposes that instructors try to consider the various difficulties during a chemistry course when students form their concepts of element conservation. (TW)

Discusses the variety of explanations in organic chemistry textbooks of a physical property of organic compounds. Focuses on those concepts explaining attractive forces between molecules. Concludes that induction interactions play a major role in alkyl halides and other polar organic molecules and should be given wider exposure in chemistry texts.…

Explains the structural organization of DNA by providing information on the primary, secondary, tertiary, and higher organization levels of the molecule. Also includes illustrations and descriptions of sign-inversion and rotating models for supercoiling of DNA. (ML)

Determined the factor structure of tasks which require students to visualize how diagrams should be drawn to represent effects of rotating three-dimensional structures about the three Cartesian axes. Results obtained from 149 English and 231 Singapore students show that visualization about X-, Y-, and Z-axes are factorially distinct. (DH)

Various typs of DNA are discussed. Areas considered include highly repetitive and satellite sequences, genes encoding, ribosomal RNA, histone protein genes, and dispersed repeated genes that jump. Regulated genetic misbehavior, structure and use of unique genes, and higher order complexities of chromosomes are also discussed. (JN)

Summarizes the structures, shapes, linkages, chain lengths, and physical and chemical properties of polymers, copolymers, and proteins with a background of knowledge of monomer units. (CC)

One application of modeling is studying the ways in which molecules fit together to form chemical compounds. Describes the forces acting between molecules and how three-dimensional graphical modeling is employed in developing rational principles for drug design. (JN)

To make material on Raoult's law more meaningful, students complete exercises on paper, in the laboratory, and with molecular models. Paper exercises give practice using the law; laboratory work illustrates behavior of real solutions; and models show relationships between properties of individual molecules and of matter in bulk. (JN)

Following a comparison of chain-growth and step-growth polymerization, focuses on the latter process by describing requirements for high molecular weight, step-growth polymerization kinetics, synthesis and molecular weight distribution of some linear step-growth polymers, and three-dimensional network step-growth polymers. (JN)

An integral equation for the s-wave bound-state solution is derived and then solved for a square-well potential. It is shown that the scattering solutions continue to exist at negative energies, and when evaluated at the energy of a bound state these solutions do reduce to the bound-state solution.

Examines the self-directed activity of two students who learned about molecular structure by writing computer programs. The programs displayed the solution of a mathematics problem, then the programs were extended to represent several classes of organic molecules. Different ways to enhance mathematical connections to chemistry education are…

Examined are some of the types of two-dimensional spectra. Their application to nuclear magnetic resonance for the elucidation of molecular structure is discussed. Included are J spectroscopy, H-H correlation spectroscopy, heteronuclear correlation spectroscopy, carbon-carbon correlation, nuclear Overhauser effect correlation, experimental…

Reviewed are two computer software packages including "ATOMS-Atomic Structure Display," and "Desktop Molecular Modeller." Discussed are hardware, components, level, cost, strengths, weaknesses, and value for teaching. (CW)

Described is how crystal field theory and the angular overlap model can be applied to very simple molecules which can then be used to introduce such concepts as bonding orbitals, MO diagrams, and Walsh diagrams. The main-group compounds are used as examples and a switch to the transition metal complexes. (KR)

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)