The thickest layer of Earth in the chemical classification is the mantle, which extends approximately 2,900 kilometers in thickness and contains a large volume due to its composition and the pressure from overlying materials.
The thickest layer of Earth in the chemical classification is the mantle. It is roughly 2,900 km thick and has an ultramafic composition, containing more iron and magnesium compared to the crust. The mantle is also larger in volume than the other chemical layers of Earth, with density increasing from about 3.5 g/cm³ to more than 5 g/cm³ due to compression from overlying material.
The core, despite being composed mainly of iron and nickel and being about 3,500 km thick, does not occupy as much volume as the mantle. The crust, on the other hand, is the thinnest and the outermost layer, with variations in thickness and density across the continental and oceanic regions.