Explore the amazing world of matter-from the earliest ideas about the four elements to the discoveries about the atom. DK gives a new look to the series that forever changed the nonfiction genre and set the standard for highly informative visual guides. This volume, and those to follow in future seasons, forms part of an indispensable library for the whole family. Focusing on contemporary and historical developments in the study of matter, this book features clear, expertly written text, color and black-and-white photos, charts, graphics, and 3-D models -- all of which combine to make complex scientific concepts easy to understand.