Seychelles Integrated Science (SIS), a 3-year laboratory-based science program for students (ages 11-15) in upper primary grades 7, 8, and 9, was developed from an extensive evaluation and modification of previous P7-P9 materials. This P8 SIS unit focuses on: (1) the uses of acids and bases (alkalis) in students' everyday lives, stressing their use at home, at work, and in the body; (2) the chemical properties of acids and bases; (3) the concept and use of the pH scales as a means of measuring acidity and alkalinity; and (4) concepts concerning the differing reactivity of metals and chemical reactions. Provided for the unit is a student workbook and a set of teaching notes. The teaching notes include the general aims of the unit, and a lesson plan for each topic area. Each lesson plan includes a suggested time frame, a list of objectives, a list of equipment needed, and a suggested lesson format. This format includes suggestions for introducing the lesson, instructional strategies (emphasizing procedures for student activities), and evaluation methods. The student workbook includes procedures for completing the unit activities and a list of new words keyed to page numbers in the workbook. (JN)