Final answer:
Option A.
The Earth is layered because during its molten state, materials separated by density, with heavier materials sinking to form the core and lighter materials rising to create the crust. This process is known as differentiation.
Step-by-step explanation:
Why is the Earth layered? The differentiation of the Earth into layers of different densities is a result of the materials separating by their density during the planet's formation.
When the Earth was molten, the heavier materials, like metals, sank towards the center, forming a dense core. At the same time, lighter materials rose to form the crust.
This layering is preserved as the Earth cools.
The moon's tidal energy and other theories, such as a snowballing effect, do not explain the Earth's internal layering.
The differences in density are apparent when comparing the Earth's overall bulk density, which is measured at approximately 5.5 g/cm³, to that of the surface materials, around 3 g/cm³.
discrepancy indicates that denser materials are located in the planet's core.
The process of differentiation ensures that over time, a planet like Earth develops distinct layers based on the composition and density of its materials.