**John T. Moore, EdD,is a chemistry professor at Stephen F. Austin State University. He's the author of many chemistry titles, including all editions of Chemistry For Dummies . ** Richard H. Langley, PhD, has been a chemistry professor at Stephen F. Austin State University for nearly 40 years. He h...

**John T. Moore, EdD,is a chemistry professor at Stephen F. Austin State University. He's the author of many chemistry titles, including all editions of Chemistry For Dummies . ** Richard H. Langley, PhD, has been a chemistry professor at Stephen F. Austin State University for nearly 40 years. He has coauthored numerous Dummies titles with John Moore.