"Why do we burp when we take a swig of soda? What are air and water actually made of? And when a liquid raw egg becomes a solid fried egg, can this change of state ever be reversible? Packed with hands-on investigations, this book explores topics including the properties of solids, liquids, and gases; how liquids become solids and how solids become liquids; how the water cycle works; why seawater is salty; and how changing states make recycling possible." --