ANSWER:
The study and analysis of light according to its component wavelengths is called spectroscopy.
Step-by-step explanation:
Spectroscopy is the branch of science that is concerned with the investigation and measurement of spectrum produced when matter interacts with or emits electromagnetic radiation.It helps us to identify atoms and molecules in the object.Spectroscopy is used to find out Dopplers effect (the red shift and blue shift),which tells how fast the object is comming towards earth or moving away from the earth.