* Iron (Fe): The most abundant element in the Earth's core, making up about 32.1% of the planet's mass.
* Oxygen (O): The most abundant element in the Earth's crust, making up about 46.6% of the planet's mass.
* Silicon (Si): The second most abundant element in the Earth's crust, making up about 27.7% of the planet's mass.
* Magnesium (Mg): The third most abundant element in the Earth's crust, making up about 2.1% of the planet's mass.
* Other Elements: The remaining mass of the Earth is made up of other elements, including aluminum, calcium, sodium, potassium, titanium, and more.
Here's a breakdown by layer:
* Core: Primarily made of iron and nickel with smaller amounts of sulfur, silicon, and oxygen.
* Mantle: Mostly silicate minerals, with some iron and magnesium.
* Crust: Mostly composed of igneous, sedimentary, and metamorphic rocks, which are all composed primarily of oxygen, silicon, aluminum, iron, calcium, sodium, potassium, and magnesium.
So while we think of Earth as a blue planet, it's mostly rock with a fiery iron core.
