The Second Edition's new co-author, Stacey Lowery Bretz, uses visualization tools—based on Chemistry Education Research, and focused on the particulate nature of matter—to help students self-assess what they know before, during, and after each chapter. Smartwork5 allows instructors to use this pedagogy as a diagnostic, and students receive hints and answer-specific feedback within the text. New ChemTour Animations support visualization at a molecular level, and are integrated throughout the media package.