Explain how Niels Bohr's observation of hydrogen's flame test and line spectrum led to his model of the atoms containing electron orbits around the nucleus?

In his observation, he notices that the hydrogen atom only emitted light of a fixed wavelength. He was able to discover that the electrons only orbit the nucleus of the atom at discrete orbits. When the electron 'jumps' from a higher to lower level orbit, it emits a wavelength. These wavelengths are unique to atoms of an element and can be used to identify them hence he led the way to the establishment of the light spectrum.