The purpose of this study is to identify how upper secondary school French students (Grade 10-12) interpret chemical transformation with regards to the changes within molecules and atoms, and in terms of intramolecular and/or intermolecular bond breaking. In order to identify and describe the students' assimilated knowledge, four questions were…

Presents various ideas on the origin of life including very early ideas, Oparin's view, and an alternative view related to carbonaceous chondrites. Outlines one currently tenable hypothesis in the formation of the solar system and explains the method involved in detecting polyatomic molecules in dark nebulae. (GS)

Explores the extent to which, in polycyclic hydrocarbons, the total pi electron population tends to form small (4n plus 2) groups and avoid the formation of 4n groups. Also discusses the relation of this trend to resonance energy stabilizations. (JN)

Describes steps (using monochiral and multichiral molecules) to enable students to arrive with relative ease at correct stereochemical relationships. The approach assumes familiarity with Fischer projection formulas and assignment of R and S absolute configurations. (JN)

Reports on recent research into the operation of neuronal local circuits in higher brain functions. (CP)

Chemical structures can be expressed unambiguously with both the atom connectivity matrix and its characteristic polynomial. (8 references) (Author)

Most knowledge of planetary atmospheres is gained through spectroscopic techniques. Information regarding what we know about several planets, particularly Jupiter, is presented. (DF)

The generator set of a group is the subset of the set of elements of the group. The nature and use of generator sets is discussed, focusing on generator sets for the noncubic symmetry point groups containing one, two, and three symmetry elements. (JN)

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.