which of the earth's layers is broken into several large tectonic plates?

The Earth's layer that is broken into several large tectonic plates is the lithosphere. The lithosphere includes the Earth's crust and the uppermost part of the mantle, forming a rigid outer shell that is fractured into major and minor tectonic plates. These plates float on the more ductile asthenosphere beneath them and move relative to each other, causing geological activity such as earthquakes and volcanic eruptions.