Light (electromagnetic wave) travels through vacuum but sound (mechanical wave) does not

Turn on the light bulb and the buzzer connected in series by which we can easily recognize the buzzer sounds and the light. Turn on the vacuum pump and remove the air from the case. As the case empties, the buzzer sounds fainter and fainter until we can barely hear it at all. After a few minutes, with no air in the case, the sound will cease but the light will not. It demonstrates the fact that the mechanical waves do not travel through vacuum whereas electromagnetic waves do.