For longitudinal waves______

The particles of the medium oscillate perpendicular to the wave’s propagation

The particles of the medium remain stationary as the wave passes through

The particles of the medium oscillate along the direction of the wave’s propagation

Their velocity is enhanced when they travel through vacuum

In longitudinal waves, the particles of the medium move back and forth in the same direction as the wave travels.

This results in compressions and rarefactions within the medium.