This experiment consists of an electric bell and a light bulb contained within a vacuum chamber. When the experiment is turned on you can hear the bell ringing and see the light glowing because the chamber still contains air. When you evacuate the air, you can still see the light waves coming out because EM waves do not require a medium for transmission but you cannot hear the bell since the air is not present to transmit the sound.

Equipment
Vacuum Bell and Jar		Vacuum Pump		Vacuum Gauge
Vacuum Lines		Extension Cord