What is one distinguishing feature of each of the four major divisions listed in your previous answer?

The four major divisions of the Earth’s layers are the crust, mantle, outer core, and inner core. The crust is characterized by its solid and brittle nature, forming the Earth's surface. The mantle is distinguished by its semi-solid, convecting rock that drives tectonic activity. The outer core is unique for being liquid and composed mainly of molten iron and nickel, while the inner core is solid due to immense pressure, consisting primarily of iron and nickel.