Q. What is the solid crust or the hard top layer of the earth called?
Answer: Lithosphere
Notes: Lithosphere is the outermost shell of earth. It includes the crust and the uppermost mantle, which constitute the hard and rigid outer layer of the Earth. The lithosphere is subdivided into tectonic plates. The uppermost part of the lithosphere that chemically reacts to the atmosphere, hydrosphere, and biosphere through the soil forming process is called the pedosphere.