In general, sound travels faster through

Solids than through gases

Gases than through solids

Empty space than through matter

Gases than through liquids

How has light been described?
as only a particle

as neither a wave nor a particle

as both a wave and a particle

as only a wave

What is amplitude?

Amplitude is the number of complete waves that pass a point in a second.

Amplitude is the height of a wave.

Amplitude is the distance between two crests or two troughs.

Amplitude is the time it takes for one complete wave to pass a given point.