Building on the Rutherford model of atom, Niels Bohr proposed a model of atom where electrons orbit around a positively charged nucleus and by applying Planck's idea of quantization, the orbits were limited to a discrete set of radii. It is an interesting fact that Bohr like Planck before him, did not believe that the light itself was quantized, until he was finally convinced, many years later, by direct experimental evidence of collisions between light quanta and electrons which is called the Compton effect.
People's ideas about the nature of light oscillated between a particle model and a wave model. Photo electric effect and the ejection of electrons from metals by light were consistent with Einstein's proposal that the energy of light was emitted and absorbed in minute packets, called quanta were named as photons. In other words, light had properties that embraced those of both particles and waves which was a totally new idea.