What is the thin, outermost layer of the Earth?

The story behind the answer

Crust is correct because it’s the Earth’s thin, outermost solid layer—only about 5–70 km thick—lying above the mantle and beneath the atmosphere. The mantle is the much thicker rocky layer below the crust, the outer core is a deep liquid iron–nickel layer, and the exosphere is the outer edge of the atmosphere, not part of the solid Earth.

Earth’s crust is broken into tectonic plates that move, causing earthquakes, mountain building, and volcanism. It comes in two types: dense oceanic crust and thicker, lighter continental crust. Remember it like an apple: the thin skin is the crust, the fleshy part is the mantle, and the core is the center.