The Earth's mantle and core have distinct differences in both mass and density.
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Mass:
- The mantle makes up about 84% of the Earth's total volume and approximately 68% of its mass. It is thick and extends from the crust to the outer core, with a depth of about 2,900 kilometers (1,800 miles).
- The core, which consists of a liquid outer core and a solid inner core, accounts for about 32% of the Earth's mass. While it is smaller in volume than the mantle, it is much denser.
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Density:
- The average density of the Earth's mantle is about 3.3 to 5.7 grams per cubic centimeter (g/cm³), depending on the depth and composition. The upper mantle is less dense than the lower mantle.
- In contrast, the core is significantly denser. The outer core has a density of about 9.9 to 12.2 g/cm³, while the inner core has an even higher density, approximately 12.8 to 13.1 g/cm³.
In summary, the Earth's core is denser than the mantle, even though the mantle has a greater mass overall. The substantial difference in density is largely due to the composition of the two layers: the core consists mainly of iron and nickel, while the mantle is composed of silicate rocks.