How do earthquakes help geologists understand Earth’s interior? During an earthquake, geologists use a machine called a
to study seismic waves.

P waves can pass through both solid and molten rock, but S waves can pass only through
rock.

During an earthquake, geologists use a machine called a SEISMOGRAPH to study seismic waves.

P waves can pass through both solid and molten rock, but S waves can pass only through SOLID rock.

Explanation:

carbon atoms, hydrogen, oxygen, and nitrogen.