Which statement best explains how density is related to the layers of the Earth?

• A. All layers of the Earth have the same density, which is why they are evenly distributed.
• B. Density does not affect the arrangement of the Earth's layers.
• C. The Earth's crust is the densest layer, while the core is the least dense.
• D. The Earth's layers are arranged according to their densities, with the densest materials found in the core and the least dense materials at the surface.

Answer: (D)

Verified step by step guidance

1. Understand that density is defined as mass per unit volume, given by the formula \(\text{density} = \frac{\text{mass}}{\text{volume}}\).
2. Recognize that the Earth is composed of different layers: the crust, mantle, and core, each with distinct compositions and densities.
3. Recall that in a gravitational field, materials tend to arrange themselves so that denser materials sink toward the center, while less dense materials rise toward the surface.
4. Apply this principle to the Earth, where the densest materials (mostly iron and nickel) are found in the core, and the less dense materials (such as silicate rocks) make up the crust and mantle.
5. Conclude that the Earth's layers are arranged according to their densities, with the densest materials at the core and the least dense materials at the surface, explaining the layering structure.