Take a look at an organized physics course. The 34-section electronic textbook covers material in AP® Physics 1 and 2. Teachers use the text to supplement lectures and have the class work through the labs. Each section contains...

Every living creature can leave a fossil record, yet most fossils belong to extinct organisms rather than ones currently living. Scholars learn about dating rock layers, fossils, and the environment of the past. Pupils understand that...

What can layers of rock teach us about the climate? Young scientists solve a mystery about who stole a cookie by applying the law of superposition. Then, they apply the same concept to solve a more difficult mystery, trying to determine...