This unit is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, which consists of two sections and an appendix, focuses on the elements and compounds of Groups I and II (the s-block) of the periodic table. The groups are treated concurrently to note comparisons between groups and to recognize trends within each group. The first section deals with the physical and chemical properties of the s-block elements. The second section examines the effect of heat on some s-block compounds, the solubility of the s-block compounds in water, and the diagonal relationship between lithium and magnesium. Several aspects of the industrial chemistry of the s-block elements are considered in the appendix. Three experiments, exercises (with answers), and pre- and post-tests are included. Students completing this ILPAC unit assume a greater responsibility for their own learning and can work, to some extent, at their own pace. By providing guidance, and detailed solutions to exercises in the units, supported by the optional use of video-cassettes, the project allows students to study A-level chemistry with less teacher contact time than a conventional course demands. (JN)