Definition
Bohr theory, proposed by Niels Bohr in 1913, is a model of the atom that describes electrons as orbiting the nucleus in specific, quantized energy levels. It suggests that electrons can only occupy certain orbits, and that they can jump between these orbits by absorbing or emitting energy. This model successfully explained the spectrum of hydrogen but had limitations for more complex atoms. It was a crucial stepping stone in the development of quantum mechanics. Bohr's model incorporated Planck's quantum theory.