I would like to clear up some confusion about the mechanics of air particles that are propagating a sound wave.
I understand that there is no net movement of air molecules when a sound wave passes through air. Instead, the particles oscillate and the wave is propagated through various elastic collisions between air molecules which cause the compression to keep moving forward.
What I don’t understand is how the air molecules move back to approximately their original position after colliding with the other particles to keep the wave moving further. Doesn’t this seemingly violate the laws of conservation of momentum? (This can’t be the case since sound exists) If a particle hits its neighbor, and that neighbor molecule now has the momentum from the wave to keep moving forward, how can the original particle have the momentum to move backward and to its original place.
I would also like to clarify that I understand gas molecules have their own random motion in addition to the wave motion and was wondering if this had something to do with the aforementioned phenomena.