Over 100 projects demonstrate composition of objects, how substances are affected by various forms of energy -- heat, light, sound, electricity, etc. Over 100 illustrations.
This book was essential to teaching explanations along with our elementary physics curriculum. We got so much more out of this book and our snap circuits than the expensive curriculum. Experiments were simple (a huge plus for a homeschool mom with less than stellar science skills). Explanations were simple but very thorough. Highly recommend!