Sound is produced when an object vibrates and can only travel through a medium, such as a solid, liquid or gas.
Sound waves are longitudinal, which means the vibrations occur parallel to the direction of wave travel. As a result, sound waves exhibit periods of compression and rarefaction.
Sound travels at different speeds, depending on the medium. Even though sound travels very fast, it is still possible to measure the speed of sound over a given distance, which is measured in metres per second (m/s).
Sound waves travel faster in media where particles are closer together. As you can see in the list above, sound travels fastest in solids, then liquids and then slowest in gases. This is because the particles of solids are closest together, then liquids and then furthest apart in gases.
When sound travels in a solid, the particles are very close together. Therefore, when particles in solids collide, they transfer energy faster than in liquids or gases.
The speed of sound waves also depends on the density of an object. The more dense an object is, the faster sound will travel through it.
Sound waves travel through the vibration of particles in a medium, whether it be air, water or solid materials. In many everyday contexts, we experience sound as vibrating air.
Since space is a vacuum with no particles to vibrate, sound cannot travel through it.