Here's why:

* Lithosphere: The lithosphere is the rigid outermost layer of Earth, composed of the crust and the uppermost part of the mantle. Mountains are formed by tectonic plate movement within the lithosphere, leading to collisions and folding of the crust.

* Other Layers:

* Atmosphere: The layer of air surrounding Earth.

* Hydrosphere: All the water on Earth, including oceans, lakes, rivers, and groundwater.

* Biosphere: All living things on Earth.

* Asthenosphere: The semi-molten layer of Earth's mantle beneath the lithosphere. While mountains are formed by forces within the lithosphere, the asthenosphere's fluidity allows the plates to move.

Let me know if you have any other questions!