Question

During the formation of Earth billions of years ago, it was very hot, and most of the material was molten or fluid, which allowed them to sink or float based on density. Imagine the Earth's layers like a density column, which layer would be most dense?

A) Crust
B) Mantle
C) Outer Core
D) Inner Core

Answer 1

The Inner Core of Earth is the most dense layer, consisting of a solid iron and nickel alloy under extreme pressure. Density decreases with distance from the core, with the mantle being less dense than the core and the crust being the least dense of all the layers.

Step-by-step explanation:

The most dense layer of Earth is D) Inner Core. The inner core is solid due to the immense pressure and is made predominantly of iron and nickel, with densities reaching very high levels. Surrounding this is the outer core, which is liquid and also very dense, but not as dense as the solid inner core.

As we move outward from the core, the next layer is the mantle, which has a lower density compared to the core. The mantle's density increases from about 3.5 g/cm³ near the top to over 5 g/cm³ closer to the core due to the pressure of the overlying material. Finally, the outermost layer, the crust, is the least dense. The continental crust has an average density of about 2.7 g/cm³ while the oceanic crust is slightly denser, around 3.0 g/cm³.

Overall, the layering of Earth according to density, with the most dense materials at the core, is a result of the early melting and differentiation that allowed heavier elements to sink towards the center, forming a dense core surrounded by lighter materials.