Here's why:

* Sound travels as vibrations: Sound waves are vibrations that travel through a medium.

* Density and stiffness matter: The speed of these vibrations depends on the density and stiffness of the material.

* Solids are denser and stiffer: Solids are denser and stiffer than liquids, allowing sound to travel through them faster.

Example: Sound travels about 1500 meters per second in water, but it travels about 5000 meters per second in steel!