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; less dense
B.
liquid; denser
C.
solid; denser
D.
liquid; less dense

Answer 1

The correct answer is: C. solid; denser.

Seismic waves travel faster in denser materials, and since P and S waves travel faster in the Earth's mantle than in the crust, this indicates that the mantle is both solid and denser than the crust.