ALERT: Before you purchase, check with your instructor or review your course syllabus to ensure that youselect 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. Student can use the URL and phone number below to help answer their questions: http: //247pearsoned.custhelp.com/app/home 800-677-6337 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. 0321934806 / 9780321934802 MasteringChemistry with Pearson eText -- Standalone Access Card -- for Chemistry: The Central Science, 13/e Package consists of: 0133888371 / 9780133888379 MasteringChemistry Content -- Access Card Package Sales Accumulator -- for Chemistry: The Central Science 0321934660 / 9780321934666 MasteringChemistry -- Pearson eText Upgrade -- for Chemistry: The Central Science 0321962656 / 9780321962652 ChemAxon -- Content -- Sales Accumulator "