The Structure and Composition of the Earth

The Earth has three layers.

From the outermost layer there is the crust, the mantle then the core.

The Crust

The crust is a rocky layer which is the thinnest of the three layers. Above the surface of the Earth is where we have discovered all the periodic elements, which are arranged in the periodic table of elements.

In the periodic table below, the element circle is iron (Fe).

We have found elements on earth that are heavier than iron. This suggests that Earth was formed from the explosion of a large star, called a supernova. This is because elements heavier than iron only form during supernova explosions.

The Mantle

The mantle has properties of a solid, it is made of mostly solid rock, however it can also flow beneath the crust. Very slowly, the hot rock rises and the cooler rock falls, which means the hot rock has a flow of convection currents.

The Core

The centre of the Earth is called the core, which is divided into the inner core and the outer core.

  • The outer core is made from liquid iron and nickel
  • The inner core is solid