In ancient times, humans used lead in everything from cooking tools to water pipes to cosmetics. That was before scientists discovered that lead is poisonous for humans. Today lead is still useful, but we use it with more care in items that hold corrosive materials, like car batteries that hold acid, or to protect us from harmful radiation, like in X-ray machines or nuclear reactors. Pb is lead's symbol, from the Latin word "plumbum." This book will help students better understand the basics of chemistry as they learn what lead is and how this toxic, but important, metal is used in our world.