What happens when you enter a room and flip the light switch? Why does a cell phone battery run down? This book focuses on electricity, electric currents, and electrical technology. Readers will learn where electric currents come from. They’ll discover some of the early pioneers in the field of electricity, including Andre-Marie Ampere and Alessandro Volta. Students will learn how inventors such as Thomas Edison and Nikola Tesla helped bring electricity into homes. Fascinating modern developments in computing and medicine will help readers see that electricity is essential. Colorful photographs and diagrams help make these complex scientific concepts more manageable for elementary readers.