How are the 3 layers identified?

Answer 1

The three layers of the Earth—crust, mantle, and core—are identified based on their composition, physical properties, and behavior under stress. The crust is the thin, solid outer layer composed primarily of rocks and minerals. Beneath it lies the mantle, a semi-solid layer that flows slowly and is made of silicate minerals. The core is divided into a liquid outer core and a solid inner core, primarily composed of iron and nickel, identified through seismic wave behavior and the study of Earth's magnetic field.