Which layer is the most dense in Earth's interior?

Which layer is the most dense in Earth's interior?

• A. Crust
• B. Mantle
• C. Outer Core
• D. Inner Core

Answer: (D)

Density within Earth's interior increases with depth due to rising pressure and the different materials each layer is made of. The solid inner core is the densest region because it’s composed mainly of iron-nickel alloy that is squeezed under the immense pressures at Earth's center, keeping it solid and highly compact. Its density is about 12.8 to 13 g/cm^3. The outer core, while still iron-nickel, is liquid and experiences slightly lower pressures, so its density is lower—roughly 9.9 to 12 g/cm^3. The mantle is much less dense, ranging around 3.3 to 5.7 g/cm^3, and the crust is the least dense, about 2.7 to 3.0 g/cm^3. Because the inner core combines both high density and a solid state under extreme pressure, it stands as the most dense layer of Earth.

Density within Earth's interior increases with depth due to rising pressure and the different materials each layer is made of. The solid inner core is the densest region because it’s composed mainly of iron-nickel alloy that is squeezed under the immense pressures at Earth's center, keeping it solid and highly compact. Its density is about 12.8 to 13 g/cm^3. The outer core, while still iron-nickel, is liquid and experiences slightly lower pressures, so its density is lower—roughly 9.9 to 12 g/cm^3. The mantle is much less dense, ranging around 3.3 to 5.7 g/cm^3, and the crust is the least dense, about 2.7 to 3.0 g/cm^3. Because the inner core combines both high density and a solid state under extreme pressure, it stands as the most dense layer of Earth.