- Bohr model (Wikipedia)
In atomic physics, the Bohr model or Rutherford–Bohr model is an obsolete model of the atom, presented by Niels Bohr and Ernest Rutherford in 1913. 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, and with the electron energies quantized (assuming only discrete values).
- Quantum mechanics (Wikipedia)
Quantum mechanics is a fundamental theory in physics that describes the behavior of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, quantum field theory, quantum technology, and quantum information science.