The fifth edition of Introduction to Chemistry continues to build on the belief that students learn best when the text and our classroom presentations focus on a conceptual approach to chemistry. This book is grounded in educational research findings that address topic sequence, context, conceptual emphasis, and concept embedded numerical problem solving. Throughout the text, content is related to students’ daily lives and shows them how chemistry allows us to understand the phenomena—both simple and complex— that we encounter on a regular basis. This text presents macroscopic chemical phenomena early and uses familiar contexts to develop microscopic explanations.