Question

Which of the following is the correct sequence of increasing average density across Earth's interior?

• A. Crust → Mantle → Core
• B. Crust → Core → Mantle
• C. Mantle → Crust → Core
• D. Core → Mantle → Crust

Answer 1

Answer:

A. Crust → Mantle → Core

• Correct Answer: Option A (Crust → Mantle → Core)

• The Earth's interior consists of three main layers with distinctly different densities. Understanding the correct sequence of increasing average density from the surface to the center is fundamental to Earth science.

• Earth's Structure and Density Distribution:

• Crust (Outermost Layer): The crust is the thinnest and least dense layer of Earth, with an average density of about 2.7-3.0 g/cm³. It consists primarily of lighter silicate rocks and minerals.

• Mantle (Middle Layer): The mantle makes up about 84% of Earth's volume and has a higher density than the crust, averaging 3.3-5.7 g/cm³. It consists of dense silicate rocks rich in magnesium and iron.

• Core (Innermost Layer): The core is the densest part of Earth, with an average density of 10-13 g/cm³. It is composed primarily of iron and nickel, which are much denser than the silicate materials found in the upper layers.