Max Planck is known for his contributions to quantum theory, especially for the development of Planck's constant and the concept of quantized energy, but he did not propose an atomic model. The atomic models were proposed by:
Bohr: The Bohr model proposed that electrons move in orbits around the nucleus, with quantized energy levels.
Sommerfeld: He extended the Bohr model by introducing elliptical orbits and explaining fine structure.
Schrodinger: He formulated the wave mechanics model of the atom, which describes the behavior of electrons as matter waves.
Thus, Planck did not propose an atomic model.
The correct option is (A): Planck