These books take an exciting new approach to physical science curriculum topics, including materials and their properties, simple machines, energy, forces and motion, electricity, sound and light, and gravity. Raintree Fusion is high-interest nonfiction aligned with curriculum, at a reading level accessible to struggling readers. It uses engaging photographs and illustrations. Background knowledge of subject matter is also incorporated into the text. All vocabulary is defined at point of use. Each title has a clean, clear design that supports readability along with clear, predictable text structures.