Scientists use the properties of seismic waves to figure out the structure of Earth's interior. For example, seismic waves travel faster through denser layers than through less dense layers. Also, P waves can travel through both solids and liquids, but S waves can travel through solids only.

Question

Because P and S waves travel faster through the Earth's mantle than through Earth's crust, scientists know that the mantle is _______ and _______ than the crust.
A.
solid; denser
B.
liquid; less dense
C.
liquid; denser
D.
solid; less dense

Answer 1

The correct answer is:

A. solid; denser

This is because seismic waves (both P and S waves) travel faster through the denser and solid layers of the Earth, which indicates that the mantle is indeed solid and denser than the crust.