What is Danish physicist Niels Bohr most famous for?

Niels Bohr is most famous for developing a more accurate model of the atom, known as the Bohr model. This model, introduced in 1913, represented a significant advancement in understanding atomic structure. It depicted the atom as having a central nucleus surrounded by electrons that travel in specific, quantized orbits at different energy levels. This was a groundbreaking idea because it incorporated the principles of quantum theory, which describes the behavior of particles at very small scales.

The Bohr model helped explain how electrons can occupy certain energy levels without radiating energy, addressing prior limitations in classical physics that could not account for the stability of atoms or the discrete lines observed in atomic spectra. This model also paved the way for future developments in quantum mechanics, influencing later theories that further refined our understanding of atomic behavior.

In contrast, the other options pertain to contributions made by other prominent physicists. For example, the theory of relativity is most famously associated with Albert Einstein, and the laws of motion are attributed to Isaac Newton. Electromagnetic radiation is a concept that involves contributions from many scientists, including James Clerk Maxwell and Heinrich Hertz. Thus, Bohr’s contribution is distinct and crucial in the context of atomic theory.