Answer:
the first line
Explanation:
A rarefaction is a region in a longitudinal wave where the particles are furthest apart. ... The region where the medium is compressed is known as a compression and the region where the medium is spread out is known as a rarefaction.
use this picture as a reference:
Answer:
Wavelength (λ) – The distance of one complete cycle in the wave. The distance between two consecutive crests and /or troughs. S.I. Unit: metre (m).
In other words:
Wavelength is the distance from crest to crest (or trough to trough).
If the reaction is a chemical change, new substances with different properties and identities are formed. This may be indicated by the production of an odor, a change in color or energy, or the formation of a solid.
A. Solar energy hope this helps