Gr 7 Up-Students who have some background in the fundamentals of chemistry will find clear-cut instructions in these two offerings. The texts are structured so that each example builds on the previous one. Plastics introduces the concept of polymers and shows how to build a model of a hydrocarbon chain. That basic concept is followed by a series of experiments that expand upon it. In the second volume, the emphasis is on understanding why water behaves the way it does molecularly. Sample projects include purification by distillation, experiments with acids and bases, and testing the power of hydrogen ions. Both titles use easily obtainable materials and common household products, and emphasize the importance of safety (including the proper disposal of chemicals). Each experiment is followed by a list of science-project ideas that will expand students' knowledge of the concepts. Black-and-white sketches help to clarify directions and provide visual interest.-Kathryn Kosiorek, Cuyahoga County Public Library, Brooklyn, OH Copyright 2004 Reed Business Information.