The earliest scientists first observed the waves that earthquakes produce before they could accurately describe the nature of earthquakes or their fundamental causes, as discussed in Lessons 1–5.

Undertake a design project to construct, test, and modify a device that either releases or absorbs thermal energy by chemical processes. In Chapter 5, students learned how the process of dissolving ...

Synthetic materials are made from natural resources. Synthetic materials are made by chemically changing the starting substances to create a material with different characteristics. Some examples of ...