Printings of the 4th edition of Friendly Chemistry made in 2016 contained some errors.  As errors were identified, they were immediately corrected and the new version sent to our printing service.  You very likely have a version with very few mistakes, if any.  However, if you find what you feel is incorrect, please check through the list below first.  If you don't find your item listed here, please contact us for assistance.  We continually update this list and thank our users for helping us improve our products.  Send your inquiries to: