Which type of wave travels through a medium by compressing and rarifying it?

Longitudinal waves travel through a medium by compressing and rarifying the particles within that medium. In this type of wave, the motion of the particles is parallel to the direction of wave propagation. When a longitudinal wave travels through a medium, regions of higher pressure (compressions) are created where particles are pushed closer together, and regions of lower pressure (rarefactions) occur where particles are spaced further apart.

This motion allows energy to be transmitted through the medium effectively. Common examples of longitudinal waves include sound waves, which travel through air, liquids, and solids, demonstrating how the medium must be present to carry the wave.

Transverse waves, on the other hand, involve particle motion that is perpendicular to the direction of wave travel, while surface waves combine properties of both transverse and longitudinal waves, typically seen in behaviors of water waves at the surface. Electromagnetic waves do not require a medium to travel, as they can move through the vacuum of space, making their propagation fundamentally different from longitudinal and transverse waves.