Question

describe an experiment to prove that sound cannot travel through vacuum

Answer 1

Sound cannot travel through avacuum. A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibrations to work in. Sound requires medium to travel. You can understand this by:

THE BELL-JAR EXPERIMENT 

For this 
*Take a jar ,put an electric bell inside it .
* Create vacuum in it.
*Turn on the bell .
*You will notice that no sound can reach your ear.

Because sound needs a medium to propogate.

Hope it helps!