Question

define sound wave and rarefaction
give correct answer​

Answer 1

$\fbox\pink{A}\fbox\blue{n}\fbox\purple{s}\fbox\green{w}\fbox\red{e}\fbox\orange{r}$Rarefaction is the reduction of an item's density, the opposite of compression. Like compression, which can travel in waves (sound waves, for instance), rarefaction waves also exist in nature. A common rarefaction wave is the area of low relative pressure following a shock wave 

Answer 2

Explanation:

ANSWER :-

One comprehension and one refraction together comprise a complete sound wave.

A region of emptiness is created as it pulls the air particles towards left. This region of low density is called their rarefaction.