The thickest layer of the earth is

The correct answer is Mantle.

Key Points

•  The Earth's thickest layer is the mantle, which stretches a bit over 1,800 miles in thickness.
• This layer makes up nearly 85% of the Earth.
• It's situated between the crust and the outer core.

Important Points

•  Layer's of earth:
  • The Inner Core
    • It is the centre and the hottest layer of the Earth. The inner core is solid and made up of iron and nickel with temperatures up to 5,500^oC. 
  • The Outer Core
    • The outer core of the Earth is similar to a very hot ball of metals, whose temperature is around 4000 ^oF to 90000F.
    • It is so hot that the metals inside are all liquid.  It is composed of metals such as iron and nickel. 
  • Mantle
    • The mantle is the widest section of the Earth. Its thickness is approximately 2,900 km.
    • The mantle is mainly made up of semi-molten rock known as magma.
    • The rock is hard in the upper part of the mantle, but lower down the rock is softer and begins to melt.
    • The mantle is located directly under the Sima. 
  • Crust
    • The crust is the outer layer where we live.
    • The thickness is around 0-60 km. It’s a solid rock layer.