What term is used for the matter through which waves travel?

• A. Medium
• B. Wave
• C. Amplitude
• D. Period

Answer: (A)

Energy moves through something called a medium—the matter that carries the wave. Many everyday waves rely on a medium: sound travels through air, earthquakes through rock, ripples through water. The medium’s particles interact and transfer energy from one to the next. In contrast, some waves like light can travel through empty space, which means no medium is required in that case. The term for the matter through which waves travel is medium. A wave is the disturbance that propagates, not the material itself. Amplitude is how far the medium’s particles move from rest, and period is the time for one full cycle. So medium best fits the description of the matter through which waves travel.