The Zimbabwe Secondary School Science Project (ZIM-SCI) developed student study guides, corresponding teaching guides, and science kits for a low-cost science course which could be taught during the first 2 years of secondary school without the aid of qualified teachers and conventional laboratories. This teaching guide, designed to be read in conjunction with the related student guide, includes instructional strategies, lists of required materials, laboratory procedures, and other information for activities and experiments in a two-part unit focusing on chemical concepts and basic laboratory skills. The ideas that matter is composed of small particles and that chemical energy is involved when these particles react are stressed throughout the unit. The first part of the unit teaches about the breaking down of substances into smaller pieces, leading to the concept of a "smallest possible" particle. The second part leads to the definition of a chemical reaction, bringing in the idea of elements and compounds. Each section in this guide corresponds to a given section in the student study guide. (JN)