Why is rubber elastic? Why are leaves green? Answering these and a myriad of other puzzles of nature, this richly illustrated volume shows how the simplest questions can lead us through a chain of reasoning that explains some of the most fascinating principles of science. Each chapter begins with a question that forms the basis for explaining a scientific principle. Step by step, the text then delves into the more sophisticated scientific matter necessary for providing insight into the question presented thus elucidating key principles and concepts. Each chapter contains a summary highlighting the salient points, answers the question definitively, and concludes with a series of exercises, including detailed solutions.