Here's why:
* Crust: This is the outermost layer, composed primarily of lighter elements like silicon, oxygen, aluminum, and iron. It's the thinnest layer and is where we live.
* Mantle: The layer beneath the crust, mostly made of denser materials like iron, magnesium, and silicon.
* Outer Core: Made mostly of liquid iron and nickel, even denser than the mantle.
* Inner Core: The densest layer, made of solid iron and nickel due to immense pressure.
The density of materials generally increases as you move deeper into the Earth. This is because the pressure from the overlying layers compresses the materials, making them denser.
