Which wave property determines loudness and pitch, and what is the nature of sound waves?

The wave property that determines loudness and pitch in sound waves is frequency.

Loudness refers to the subjective perception of the intensity or amplitude of a sound wave. The greater the amplitude of a sound wave, the louder it is perceived to be. However, the physical property that directly correlates with loudness is intensity, which is determined by the amplitude of the sound wave. Higher amplitudes correspond to greater intensity and louder sounds.

Pitch, on the other hand, is determined by the frequency of a sound wave. Frequency refers to the number of cycles or vibrations of a wave that occur in a given time period. In the case of sound, it corresponds to the number of compressions and rarefactions of air molecules per second. Higher frequencies result in higher-pitched sounds, while lower frequencies produce lower-pitched sounds.

Sound waves themselves are mechanical waves that require a medium, such as air, water, or solids, to propagate. They are created by vibrating objects, which cause adjacent molecules in the medium to vibrate in a chain reaction. These vibrations create areas of compression (where molecules are close together) and rarefaction (where molecules are spread apart) as they travel through the medium. Sound waves are longitudinal waves, meaning the vibrations occur parallel to the direction of wave propagation.