"A bowling ball is heavy. A feather is light. Why are some items heavy and others light? Find out in this series about materials and their properties. Informative, at-level text and engaging photographs help readers understand the differences between heavy and light materials"--Provided by the publisher.

"A piece of silk is smooth. Tree bark is rough. Why are some objects smooth and others rough? Find out in this series about materials and their properties. Informative, at-level text and engaging photographs help readers understand the differences between smooth and rough objects"--Provided by the publisher.

"A rubber duck floats in the tub. A rock sinks to the bottom of a lake. Why do some objects float and others sink? Find out in this series about materials and their properties. Informative, at-level text and engaging photos help readers understand the differences between objects that sink and float"--Provided by the publisher.