Book 1

What Is a Gas?

by Jennifer Boothroyd

Published 1 January 2007

Book 2

What is a Liquid?

by Jennifer Boothroyd

Published 1 January 2007
Simple text and color photographs describe the properties of liquid.

Book 3

What is a Solid?

by Jennifer Boothroyd

Published 1 January 2007
Discusses the properties of solids and how they differ from gases and liquids.