This book is a guide to key concepts in O-Level Chemistry based on the latest MOE syllabus. It summarises all the key concepts that students need to understand before the examination. It contains scientific keywords that is required to show understanding when answering the questions in tests and examinations.Important Chemistry concepts are presented in simple and concise points for quick and easy reference, making it ideal for quick revision before a test or an examination. Relevant examples and diagrams are also provided to facilitate the understanding of important Chemistry concepts.