Sound travels in air if disturbance moves.
Explanation: When a sound wave travels through air, the individual air particles don’t actually travel long distances; instead, the disturbance caused by the initial vibration travels, causing the nearby particles to vibrate in turn, propagating the wave. This disturbance is what carries the sound.
Why other options are incorrect:
A – Particles of medium travel from one place to another:
While the particles do vibrate, they don’t move large distances themselves. It’s the disturbance that travels.
B – There is no moisture in the atmosphere:
Moisture content doesn’t directly affect sound propagation. Sound can travel through both dry and humid air. The presence of moisture might influence the speed of sound slightly, but it doesn’t determine whether sound can travel at all.
D – Both particles as well as disturbance travel from one place to another:
The particles do vibrate and move locally, but the primary movement is of the disturbance. If both particles and the disturbance moved long distances, the sound would be much faster than it actually is.