Sound waves, unlike electromagnetic waves, cannot travel through vacuum. Why?

Explanation

Sound is produced by the mechanical vibration of a body. Mechanical vibrations need material medium with inertia and elasticity to sustain it for propagation. Hence, sound wave cannot travel through vacuum. On the other hand, electromagnetic waves are set up due to oscillation of electric and magnetic field. Electric and magnetic field can spread without any medium. Hence, electromagnetic waves can travel through vacuum.