Answer:
a) Addition reaction, is your answer
Doppler effect is the compression or extension of a sound wave, which causes a change in its wavelength / frequency (and so its sound).
Explanation: It is defined as the effect produced by a moving source of waves in which there is an upward shift in frequency for observers, the source is moving towards and downward shift of frequency from which the source is moving away. used to tell if an object in space is moving toward or away from us.
Answer:
A product in science is a substance that is formed when two or more chemicals react.
Explanation:
When a chemical reaction takes place, a new substance is often created from the atoms or molecules of the original substances. There are often multiple products formed in a reaction.