NSES Content Standard D 
Earth and Space Science: Structure of the Earth system
Grades 5-8, page 159

The solid Earth is layered with a lithosphere; hot, convecting mantle; and dense, metallic core.
 

 
Benchmark 4C The Physical Setting: Processes that Shape the Earth
Grades 6-8, page 73
The interior of the earth is hot. Heat flow and movement of material within the earth cause earthquakes and volcanic eruptions and create mountains and ocean basins. Gas and dust from large volcanoes can change the atmosphere.

Benchmark 4C The Physical Setting: Processes that Shape the Earth
Grades 9-12, page 74
The solid crust of the earth--including both the continents and the ocean basins--consists of separate plates that ride on a denser, hot, gradually deformable layer of the earth. The crust sections move very slowly, pressing against one another in some places, pulling apart in other places. Ocean-floor plates may slide under continental plates, sinking deep into the earth. The surface layers of these plates may fold, forming mountain ranges.