1. Atmosphere: The outermost layer, composed primarily of nitrogen and oxygen, is the least dense.
2. Crust: The thin, rocky outer layer of the Earth, composed of mostly lighter elements like silicon and aluminum.
3. Mantle: The thickest layer, composed primarily of denser minerals like iron and magnesium silicates.
4. Outer Core: A liquid layer composed mainly of iron and nickel, with even higher density than the mantle.
5. Inner Core: The solid, extremely dense center of the Earth, primarily composed of iron and nickel, under immense pressure.
Key takeaway: Density generally increases as you move deeper into the Earth due to the immense pressure squeezing the materials together.
