ALERT: Before you purchase, check with your instructor or review your course syllabus to ensure that you select the correct ISBN. Several versions of Pearson's MyLab & Mastering products exist for each title, including customized versions for individual schools, and registrations are not transferable. In addition, you may need a CourseID, provided by your instructor, to register for and use Pearson's MyLab & Mastering products. Packages Access codes for Pearson's MyLab & Mastering products may not be included when purchasing or renting from companies other than Pearson; check with the seller before completing your purchase. Used or rental books If you rent or purchase a used book with an access code, the access code may have been redeemed previously and you may have to purchase a new access code. Access codes Access codes that are purchased from sellers other than Pearson carry a higher risk of being either the wrong ISBN or a previously redeemed code. Check with the seller prior to purchase. -- The text that defined the liberal arts chemistry course, Chemistry for Changing Times remains the most visually appealing and readable introduction on the subject. Now available with MasteringChemistry®, the Thirteenth Edition increases its focus on student engagement—with revised “Have You Ever Wondered?” questions, new Learning Objectives in each chapter that are linked to end of chapter problems in the text and to MasteringChemistry questions, and expanded Green Chemistry content. Abundant applications and examples fill each chapter, and material is updated throughout to mirror the latest scientific developments in a fast-changing world. Compelling chapter opening photos, a focus on Green Chemistry, and the “It DOES Matter!” feature reflect current events and enable students to relate to the text more readily.