Explain how the understanding of atomic emission spectrum led to development of the atomic theory

It was Niels Henrik David Bohr, a Danish physicist, analyzed the atomic emission spectrum of hydrogen and showed mathematically that this was the result of movement of e- from a specific energy level to a lower energy level. This became the accepted theory that electrons could only be in specific locations and these locations corresponded to energy levels 1st energy level, 2nd energy level, etc.