Question

how can u show that sound can not travels through vaccum

Answer 1

in space , where u find only vacuum , one cannot hear wat other speaks , hence itz said dat sound cannot travel through vacuum they need a material medium for itz propagation

Answer 2

when we keep an alarm bell in a glass chamber (in which vaccum is there) and ring the bell, we will not hear the ringing sound. this shows that sounds cannot travel in vaccum.