Part 5/11:
In a stroke of brilliance, Bohr proposed a revolutionary concept: electrons occupy specific quantized energy levels rather than moving freely. This daring leap began the evolution of quantum mechanics, culminating in his publication of three pivotal papers in 1913 that would lay the foundation for the new field. The scientific community erupted—his theories synthesized existing knowledge and offered explanations for phenomena, such as the spectral lines of hydrogen, that had baffled physicists for years.