Scientific discovery is powered by questioning minds. This useful series harnesses kids natural curiosity to explore subjects from the 2nd and 3rd grade physical science curricula. Each book opens with an introduction to an important physical science topic. Then, the author raises and answers 20 interesting questions about that topic. Colorful photographs and diagrams will help kids grasp the important scientific concepts introduced throughout the series. A glossary, index, and web site that links to more information offer additional opportunities for young readers to expand their knowledge.