Gases

Earth is made of different things—gases, rocks, soil, and water. A gas is something that can change shape and size. Gases helps beginning readers understand this basic element by looking at examples such as air and steam; the book also discusses how gases help protect the Earth. Air pollution......Page 21 Great gas facts......Page 22 Glossary......Page 24 Index......Page 25 Copyright info......Page 26 A very simple introduction to what gases are, giving examples of some different kinds