An introduction to the noble gases and chemical bonding via Lewis theory and the octet rule are common inclusions in secondary school curricula. However, the usual approach may lead to misconceptions and difficulties when valence bond (VB) theory and valence shell electron pair repulsion (VSEPR) theory are taught at a later pre-university stage.…

This article argues that we need to make use of our everyday experiences when introducing concepts in chemistry that are often obscure. It uses reaction rates as an example and explores a common misconception related to the explanation of the effect of rising temperature on the rate of slow reactions.

Students often struggle to determine whether changes in matter are physical or chemical; for example, they may have difficulty labelling a candle melting as a physical change but a candle burning as chemical change. Here we describe a lesson that we used to integrate conceptual learning about physical and chemical changes using the…

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)