Here's why:

* Lithosphere: This is the rigid outermost layer of the Earth, composed of the crust and the uppermost part of the mantle. It's broken into large pieces called tectonic plates. These plates move slowly over time, causing earthquakes, volcanic eruptions, and the formation of mountains and ocean trenches.

* Other layers: The other layers of the Earth, such as the asthenosphere (upper mantle), mesosphere (lower mantle), outer core, and inner core, are not broken into pieces.