This book aims to cover the specifications of the main examination boards for GCSE Double Science, GCSE Single Science and the core content of GCSE Chemistry. Where relevant, Key Stage 3 material is summarized as an introduction to GCSE topics. This serves as revision of work done prior to Key Stage 4, and a foundation for GCSE studies. The book is also useful to teachers as a handy reference and planner. Each page is presented diagrammatically in an attractive way using illustrations, tables and some photographs. Diagrammatic presentations are used as much as possible in order to make it easier for students to recall information and understand the principles involved. Bullet points and questions are used to emphasize the essential content of each page. There are also review questions for every section.