John T MooreJohn T. Moore, Ed.D., teaches chemistry at Stephen F. Austin State University in Austin, Texas. He is the author of numerous books on chemistry and. Has served as AP Chemistry reader and chemistry and physical science questions writer for the ollege Board for many years.Richard Langley, PhD, teaches chemistry at Stephen F. Austin State University in Austin, Texas. He has been a grader for the AP Chemistry exams for over 20 years and is the author or co-author of several chemistry books and research papers. Read More Read Less