Can mechanical waves travel through vacuum?

Sound can travel through

Can sound travel in vacuum?

A plane electromagnetic wave travels in vacuum along z-direction. What can you sayabout the directions of its electric and magnetic field vectors? If the frequency of the wave is 30 MHz, what is its wavelength?

A plain electromagnetic wave travels in vacuum along the Y-direction. Write the the directions of its electric and magnetic field vectors.

A plain electromagnetic wave travels in vacuum along the Y-direction.Write the ratio of the magnitudes of its electric and magnetic filed vectors.