What is vaccum? Explain why, sound cannot travel through vaccum?

Why sound cannot travel through vacuum ?

Why sound wave cannot travel through vaccum?

Heat travels through vaccum by

Can sound waves travel through vaccum ?

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

In the following statements ,tick 'T' against those which are true and 'F' against those which are false. Sound cannot travel in vaccum. (T/F)

In the following statements ,tick 'T' against those which are true and 'F' against those which are false. Sound cannot travel in vaccum. (T/F)

A photon of light enters a block of glass after travelling through vaccum. The energy of the photon on entering the glass block