Niels Bohr and Ernest Rutherford in 1913.
A model of the atom in which electrons orbit the nucleus in discrete energy levels or shells.
Historical background of atomic theory: A brief history of the evolution of the atomic theory from ancient times to the present day.
Quantum mechanics: The fundamental concepts of quantum mechanics including wave-particle duality, uncertainty principle, and superposition.
Bohr's postulates: The five postulates proposed by Niels Bohr to describe the atomic structure.
Bohr's model: The Bohr model of the atom and its implications.
Energy levels: The concept of energy levels and their significance in the atomic structure.
Electromagnetic radiation: The nature and properties of electromagnetic radiation including its wave nature and wave properties.
Spectroscopy: The principles of spectroscopy and its relationship to the atomic structure.
Atomic spectra: The structure of atomic spectra and their relevance to Bohr's model.
Hydrogen atom: The structure and properties of the hydrogen atom.
Electron transitions: The various electron transitions that occur in atoms and their impact on the atomic spectra.
Quantum numbers: The concept of quantum numbers and their significance in describing the atomic structure.
Uncertainty principle: The significance of the uncertainty principle in determining the properties of atoms.
Pauli's exclusion principle: Pauli's exclusion principle and its application in the description of the atomic structure.
Spin and magnetic moment: The concept of spin and magnetic moment in atoms and their importance in atomic physics.
Wave functions: The concept of wave functions and their role in describing the atomic structure.
"It consists of a small, dense nucleus surrounded by orbiting electrons."
"It is analogous to the structure of the Solar System."
"But with attraction provided by electrostatic force rather than gravity"
"The electron energies are quantized, assuming only discrete values."
"Joseph Larmor's Solar System model (1897), Jean Perrin's model (1901), the cubical model (1902), Hantaro Nagaoka's Saturnian model (1904), the plum pudding model (1904), Arthur Haas's quantum model (1910), the Rutherford model (1911), and John William Nicholson's nuclear quantum model (1912)."
"The improvement over the 1911 Rutherford model mainly concerned the new quantum mechanical interpretation introduced by Haas and Nicholson."
"The Bohr model explained the reasons for the structure of the Rydberg formula."
"Not only did the Bohr model explain the reasons for the structure of the Rydberg formula, it also provided a justification for the fundamental physical constants that make up the formula's empirical results."
"The Bohr model is a relatively primitive model of the hydrogen atom, compared to the valence shell model."
"It can be derived as a first-order approximation of the hydrogen atom using the broader and much more accurate quantum mechanics."
"Yes, it may be considered to be an obsolete scientific theory."
"Because of its simplicity, and its correct results for selected systems, the Bohr model is still commonly taught to introduce students to quantum mechanics or energy level diagrams."
"Arthur Erich Haas proposed a related quantum model in 1910."
"It was thoroughly discussed at the 1911 Solvay Congress."
"The quantum theory of the period between Planck's discovery of the quantum (1900) and the advent of a mature quantum mechanics (1925) is often referred to as the old quantum theory."
"While the Rydberg formula had been known experimentally, it did not gain a theoretical basis until the Bohr model was introduced."
"But forsaking any attempt to explain radiation according to classical physics."
"Attraction provided by electrostatic force rather than gravity."
"The model's key success lay in explaining the Rydberg formula for hydrogen's spectral emission lines."