Sound is transmitted by particles vibrating and passing kinetic energy to neighbouring particles through intermolecular forces. In a solid, particles are tightly packed and held together by strong bonds. When one particle is displaced, it almost immediately pulls or pushes the next one — the "message" travels quickly. Think of a row of magnets on a table: push one and the force is transmitted nearly instantly along the row.
In a gas, molecules are far apart and interact weakly. A displaced molecule must travel some distance before it collides with the next one. This makes energy transfer slower — hence slower sound speed in gases. Liquids are intermediate: particles are close but not rigidly bonded.
Temperature also matters: warmer air has faster-moving molecules, so energy is transferred between molecules more quickly, increasing the speed of sound.
This how it works covers How It Works: Why Sound Travels Faster in Solids within Sound Waves for GCSE Physics. Revise Sound Waves in Waves for GCSE Physics with 16 exam-style questions and 15 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 6 of 13 in this topic. Use this how it works to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Sound Waves
What type of wave is sound?
Describe how a sound wave is produced and how energy is transferred by a longitudinal wave.