Sound is a longitudinal wave; it is created when the air surrounding it vibrates. Sound waves need to travel through a medium such as a solid, liquid, or gas, but they can’t travel through a vacuum. Sound is a type of energy caused by vibrations, it moves through each of these mediums by vibrating the molecules in the matter. The molecules in solids are jammed very tightly together meaning the sound travels faster through denser solids. Liquids are not as tightly packed as solids meaning the sound travels slower than in a solid. Gases are very loosely packed meaning that sound travels through gasses slower than solids and liquids. A vacuum is an empty space without any molecules, because there are no molecules there is nothing to vibrate the
