Young people intuitively understand that matter takes different forms - water, for example, can be liquid, solid ice, or gaseous steam. This book will give readers a deeper understanding of the different states of matter. Through colorful photographs and lively discussions of familiar materials, readers will be drawn in to learn about matter's many forms. Topics include - understanding matter, mass, volume, and density - differences between solids, liquids, and gases - how matter passes from one state to another - properties of matter, such as hardness and viscosity. Teacher's guide available.