I apologize for the confusion, but there seems to be a misunderstanding. Niels Bohr did not formulate a theorem specifically related to atoms. However, Niels Bohr made significant contributions to atomic theory through his atomic model, known as the Bohr model or Bohr's atomic theory. The Bohr model provided a framework for understanding the structure and behavior of atoms based on the principles of quantum mechanics. Here's an explanation of Bohr's atomic model:
Bohr's atomic model, proposed in 1913, was developed to explain the stability of atoms and the observed line spectra of elements. The key postulates of Bohr's model are as follows:
Energy levels: Bohr suggested that electrons in an atom occupy specific energy levels or orbits around the nucleus. Each energy level corresponds to a particular fixed amount of energy. Electrons closer to the nucleus are in lower energy levels, while those farther away occupy higher energy levels.
Quantized energy: Bohr proposed that electrons can only exist in these specific energy levels and not in between. This implies that electrons can transition between energy levels by either absorbing or emitting energy in discrete packets called quanta or photons. The energy of a photon is directly related to the difference in energy between the initial and final energy levels.
Stability of orbits: Bohr's model introduced the concept of stationary or stable orbits. Electrons can revolve around the nucleus in these stable orbits without emitting energy. According to classical electromagnetism, an accelerating charged particle would continuously lose energy through radiation and eventually spiral into the nucleus. However, Bohr suggested that electrons can remain in stable orbits without emitting radiation, as long as they are in one of the allowed energy levels.
Correspondence principle: Bohr's model also incorporated the correspondence principle, which states that the predictions of the new quantum theory should match the predictions of classical physics in the limit of large quantum numbers or high energy levels. This principle helped bridge the gap between classical and quantum physics.
Bohr's atomic model was a significant step towards understanding the behavior of electrons in atoms and provided a framework for subsequent developments in quantum mechanics. It laid the foundation for further refinements in atomic theory, such as the quantum mechanical model, which replaced the notion of well-defined orbits with probability distributions of electron positions known as atomic orbitals.