Final answer:
The layers of Earth defined by its compositional structure, in the correct order from external to internal, b. are crust, mantle, and core.
Step-by-step explanation:
b. The layers of Earth categorized by its compositional structure, in the correct order from external to internal layers, are:
- Crust: Earth's outer surface, made of rock and divided into two types: continental and oceanic crust. Continental crust is thicker, less dense, and composed mainly of granite. Oceanic crust is thinner, denser, and composed mainly of basalt.
- Mantle: The layer surrounding the core, less dense than the core, and consists of solid rock that can behave in a plastic (deformable) manner.
- Core: Divided into two parts: the outer core, which is liquid and composed of iron and nickel, and the inner core, which is solid and also composed of iron and nickel.