layers of the earth

• 1. The inner core is in the centre and is the hottest part of the Earth. It is solid and made up of iron and nickel with temperatures of up to 5,500°C .This is due to the relative melting points of the different layers (nickel–iron core, silicate crust and mantle) and the increase in temperature and pressure as depth increases
• 1. The outer core is the layer surrounding the inner core. It is a liquid layer, also made up of iron and nickel.
• 1. The mantle is the thickest section of the Earth at approximately 2,900 km. The mantle is made up of semi-molten rock called magma.
• The crust is the thinnest layer of the Earth and is the layer we live on. made up of a variety of rocks and can reach up to 70km thick in places. crust itself is divided into large chunks eg tectonic plates.  There are around 7 large and 12 small plates, which ‘float’ on top of the mantle beneath them. 
• The plates themselves are made up of 2 different types of crust, continental crust under the land and oceanic crust under the sea.Continental crust is thick(25-70 km) and light cause it is made of rocks with a low density. Oceanic crust is thin (6-11km) and heavy because it is made of rocks (mostly volcanic rocks) that have a high density.oceanic crust covers 2/3 of the Earth’s surface.