Final answer:
The incorrect description is that the mantle is the innermost part of the Earth; the innermost part is actually the core. The mantle is beneath the crust and surrounds the core.
Step-by-step explanation:
The incorrect description of Earth's interior in the options provided is "Mantle is the innermost part of the Earth." The Earth's interior is composed of several layers, with the core being the innermost part. The core itself is split into two: the inner core, which is a hot, solid sphere made of metal, specifically an alloy of iron and nickel, and the outer core, which is a shell of hot, liquid metal surrounding the inner core.
Above the core is the mantle, which is not as dense as the core and consists of solid rock that can behave in a plastic manner under high pressure and temperature. The crust is the outermost thin layer of the Earth, with oceanic crust being thinner and denser than the continental crust. Therefore, the mantle is not the innermost but rather surrounds the core and is below the crust.