Reports on a low-cost and unique molecular model set capable of generating a large number of structures for teaching and learning general chemistry. An important component of the kit is an 11-hole ball that gives tetrahedral, octahedral, trigonal, trigonal bipyramidal, and square planar symmetries. (WRM)

Information about the control of the activity of the 2-oxoglutarate dehydrogenase complex (OGDHC), a key enzyme in the citric acid cycle, is not well covered in the biochemical education literature, especially as it concerns the allosteric regulation of OGDHC by adenine nucleotide and ortophosphate. From experimental work published during the last…

Overviews of the observations that constitute a structure proof for penicillin, specifically aimed at the general student population, are presented. Melting points and boiling points were criteria of purity and a crucial tool was microanalysis leading to empirical formulas.

A survey of introductory textbooks shows that many authors fail to connect explicitly their discussions of empirical versus molecular formulas with their latter discussions of the composition and structure of nonmolecular solids. A study proposes that some method, such as the use of quotation marks, be adopted to differentiate unambiguously…

The time-resolved fluorescence experiment investigating the halide quenching of fluorescence from quinine sulfate in water is described. The objectives of the experiment include reinforcing student understanding of the kinetics of competing pathways, making connections with microscopic theories of kinetics through comparison of experimental and…

Nanometer-scale investigations offer the potential of providing first-principles understanding of tribo-systems in terms of fundamental intermolecular forces. Some of the basic issues and motivation for use of scanning probes in the area of nanotribology is presented.

Harold Kroto is professor of chemistry at Sussex University and President of the Royal Society of Chemistry (UK), offers an insight into the way his discoveries, and his interpretation, were influenced by his other interests in the wider fields of chemistry and by his passionate interest in art. He shares his views on the discovery of…

Packing efficiency and crystal density can be calculated from basic geometric principles employing the Pythagorean theorem, if the unit-cell structure is known. The procedures illustrated have applicability in courses such as general chemistry, intermediate and advanced inorganic, materials science, and solid-state physics.

The canny world of advertising has caught on to the free radical theory of aging, marketing a whole array of antioxidants for preventing anything from wrinkles to dry hair to reducing the risk of heart disease--promising to help slow the hands of time. Working with genetically engineered mice--to produce a natural antioxidant enzyme called…

Some innovations in the images of cells and molecules that keep changing for new techniques and as a result of using new approaches to old methods are explored and new ways of illustrating cell and molecular structures are discussed. The three elements that play an important role in any biological image are aesthetic factors such as picture style…

The Dumas method provides a relatively simple way to determine the molar mass of volatile chemical compounds. A potential source of error in the Dumas molar mass method as it is often practiced in introductory chemistry laboratories is reported.

The introduction of chirality in one and two dimensions, along with the concepts of internal and external reflection, can be combined with concepts familiar to all students. Once familiar with 1-Dimensional and 2-Dimensional chirality, the same concepts can be extended to 3-Dimensional and by projecting 3-D back to two, it is possible to interpret…

The importance of chemistry in daily life of the students is discussed. The approach provides a connection between the details of molecular structure, bonding and reactivity with many aspects of the impact of chemistry on the society.

A two-minute overhead demonstration using a molecular model kit is employed for illustrating the unique binding of cyclopropane. It is reported that most model kits, much like an sp (super 3) hybridized carbon atom, resist forming 60-degree bond angles.

A multipurpose apparatus that can be used to measure the viscosity of solution by the Ostwald method and the surface tension of solution by the drop-weight method or by the capillary-rise method is developed. The apparatus is convenient for in-situ preparation of solutions of different concentrations and avoids the error that frothing of the…