1. Crust:
* Composition: Primarily composed of relatively light elements like silicon, oxygen, aluminum, iron, calcium, sodium, potassium, and magnesium.
* Sub-layers:
* Oceanic crust: Thinner, denser, and younger, composed mainly of basalt (volcanic rock).
* Continental crust: Thicker, less dense, and older, composed mainly of granite (igneous rock).
2. Mantle:
* Composition: Mostly composed of silicate minerals rich in iron and magnesium.
* Sub-layers:
* Upper mantle: Includes the lithosphere (rigid outer layer) and the asthenosphere (semi-molten, flowing layer).
* Lower mantle: More solid and denser than the upper mantle.
3. Outer Core:
* Composition: Liquid iron and nickel, with smaller amounts of sulfur, silicon, and oxygen.
* Key characteristic: Responsible for Earth's magnetic field.
4. Inner Core:
* Composition: Solid iron and nickel, with trace elements.
* Key characteristic: Extremely hot and under immense pressure, despite being solid.
Important Note: While we can describe these layers based on their chemical composition, remember that the boundaries between them are not sharp and defined lines. There are transitional zones with gradual changes in composition and physical properties.
