The second edition's new co-author, Stacey Lowery Bretz, uses visualisation 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 visualisation at a molecular level and are integrated throughout the media package.