the lithosphere also known as the crust. it is broken into seven different rigid pieces called plates. which include North America, South America, Australia, Antarctic and etc. the lithosphere is very brittle and Light and moves because of convection currents in the lower layer of the mantle. another reason that the lithosphere is brittle is because it has to deal with natural disasters on contact like earthquakes which breaks the lithosphere into several peices making it weaker than the other layers.
(I hope this helps answer your question! Have a great day everyone!)
