Discusses the problem of symmetry avoidance using water as an historical example. Uses simple pi systems for the analysis. Provides methodology and examples. Investigates two naive arguments. (MVL)

Points out a misconception that is reinforced in many elementary and advanced chemistry texts. Discusses the general limitations of the orbital concept. Notes misconceptions related to the transition elements and their first ionization energies. (MVL)

Presents the mechanistic ideas underlying reactions between nucleophiles and carbonyl compounds as well as some popular misconceptions. Relates reactions of carboxylic acid derivatives to those of aldehydes and ketones. Discusses leaving group ability and the ability of carbonyl oxygen to accept a negative charge. (Author/MVL)