State three characteristics of the medium required for propagation of sound?

The characteristics of the medium required for propagation of sound in a medium are —

(a) The medium must be elastic so that it's particles may come back to their initial position after displacement on either side, i.e., the particles are capable of vibrating about their mean position.

(b) The medium must have inertia so that it's particles may store mechanical energy.

(c) The medium should be frictionless so that there is no loss of energy in propagation of sound through it.