The inner core is solid and is 90% iron, but the outer core is a liquid...and it's a good thing it is! More on that later. The outer core is made of a mixture of iron and nickel, with smaller amounts of silicon and oxygen.
The crust
This is the outside layer of the earth and is made of solid rock, mostly basalt and granite. There are two types of crust; oceanic and continental. Oceanic crust is denser and thinner and mainly composed of basalt. Continental crust is less dense, thicker, and mainly composed of granite.
The mantle
The mantle lies below the crust and is up to 2900 km thick. It consists of hot, dense, iron and magnesium-rich solid rock. The crust and the upper part of the mantle make up the lithosphere, which is broken into plates, both large and small. To learn more about these plates see the Plate Tectonics page.
The core
The core is the centre of the earth and is made up of two parts: the liquid outer core and solid inner core. The outer core is made of nickel, iron and molten rock. Temperatures here can reach up to 50,000 C.
Explanation:
Inner Core: The innermost part of Earth is the core and is about 1500 miles (2414 km) thick. ... Outer Core: The outer core, which is liquid, is about 1300 miles (2092 km) thick. Both the inner and outer cores consist primarily of iron and nickel and are extremely hot with temperatures ranging from 7200–9000℉ (4000–5000℃).
