What is the internal structure of the earth?

The earth is made up of several layers, and they differ greatly in chemical composition, physical condition and thickness. The surface of the planet is called the earth’s crust, it is solid, but not very thick. Then comes a layer called the mantle, which is more than half the planet’s weight. The substance in the mantle has a liquid structure. Below it is the planet’s outer core, which is made up mostly of iron. And inside it is the last layer, the inner core, which consists of an iron-nickel alloy.