The eight elements that make up the Earth's crust occur in the crust layer of the Earth.

Here's why:

* Crust: The outermost layer of the Earth, composed primarily of lighter elements like oxygen, silicon, aluminum, iron, calcium, sodium, potassium, and magnesium. These eight elements make up about 98.5% of the Earth's crust.

* Mantle: The layer beneath the crust, composed of denser materials like iron and magnesium.

* Core: The innermost layer, consisting of a solid inner core and a liquid outer core, primarily made up of iron and nickel.

Therefore, the elements that make up the Earth's crust are found in the crust itself.