The main purpose of this guidebook is to enable students to master Chemistry effectively and efficiently. It incorporates insights the authors have acquired from their many years in teaching the subject in schools. Within a topic, subtopics are carefully sequenced to build on existing prior knowledge and ensure a good grasp of fundamental Chemistry concepts. This prevents misconceptions that is one of the pitfalls of many students. This guidebook not only meets the requirements of the revised GCE O-Level Chemistry Syllabus but is also highly relevant to students who are in the Integrated Programme.