Here's why:

* Solids have particles packed tightly together. This allows sound vibrations to pass quickly from one particle to the next.

* Liquids have particles that are farther apart than solids, so vibrations take a bit longer to travel.

* Gases have particles that are spread out even further, meaning sound travels slowest in gases.

Here's a general order of speed of sound from slowest to fastest:

* Gases

* Liquids

* Solids

Example: Sound travels about 1,500 meters per second in water, but about 5,100 meters per second in steel.