The chemistry of dissolved inorganic carbon in seawater is reviewed and used to predict the potential effect of rising levels of carbon dioxide in the atmosphere. In agreement with more detailed treatments, we find that calcium carbonate (aragonite) may become unsaturated in cold surface seawater by the year 2100 C.E., resulting in the destruction…

A facile synthesis of two gold(I) complexes with 1,2-benzenedithiolate ligand and two different bidentate phosphines are described. A detailed sequence of NMR experiments is suggested to determine the structure of the compounds.

Self-assembly or spontaneous assembly is a process in which materials build themselves without assistance. This process plays a central role in the construction of biological structures and materials such as cells, viruses, and bone, and also in abiotic processes like phase transitions and crystal formation. The principles of self-assembly help…

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)

The DNA triplet code also functions as a binary code. Because double-ring compounds cannot bind to double-ring compounds in the DNA code, the sequence of bases classified simply as purines or pyrimidines can encode for smaller groups of possible amino acids. This is an intuitive approach to teaching the DNA code. (Contains 6 figures.)

A method of plotting planes on stereonets is described including great circles, poles, and dip vectors. Teaching applications of dip vectors in engineering geology and structural geology are discussed. (CW)

Describes a set of simple, inexpensive, classical demonstrations of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) principles that illustrate the resonance condition associated with magnetic dipoles and the dependence of the resonance frequency on environment. (WRM)

This paper reports the results of applying a particular analytical perspective to data from an interview study: a typology of learning impediments informed by research into learning and students' ideas in science. This typology is a heuristic tool that may help diagnose the origins of students' learning difficulties. Here it is applied to data…

A project involving the synthesis of several naturally occurring copper double salts using simple aqueous conditions is reported. The ions present in the compound are analyzed using colorimetric, gravimetric, and gas-analysis techniques appropriate for the first-year laboratory and from the percent composition, the empirical formula of each…

Presents coulombic models representing the particles of a system by point charges interacting through Coulomb's law to explain coulombic lattice potential. Uses rubidium manganese trifluoride as an example of cubic perovskite structure. Discusses the effects on cluster properties. (CW)

Compares the similar mathematical problems of molecular vibrational calculations (at any intermediate level of sophistication) and molecular orbital calculations (at the Huckel level). Discusses how the generalizations of Huckel treatment of molecular orbitals apply to vibrational theory. (TW)

Presents the exploded structure method for determination of oxidation states in covalently bound atoms. The three step method is illustrated with four examples and compared to popular textbook presentations. (JM)

Describes a method for demonstrating absorption spectra of intensely colored solutions using a mounted grating and a specially designed cell. Allows a student to compare the spectrum of a white light source directly with the same light modified by an absorbing spectrum. Uses acrylic tubing to make the cell. (MVL)

Discussed is an extension of the conventional method for studying the organometallic chemistry of transition metals that may be useful to show how the various existing types of low-valence complexes can be constructed. This method allows students to design new types of complexes that may still be nonexistent. (CW)

The use of crude flower extracts to the principle of analytical chemistry automation, with the flow injection analysis (FIA) procedure developed to determine hypochlorite in household bleaching products was performed. The FIA comprises a group of techniques based on injection of a liquid sample into a moving, nonsegmented carrier stream of a…