Engineering Physics Annotation << Back Part II. Bound electron and the parameters of its orbit in the hydrogen atom Igolkin S.I. Classical Bohr orbit model is used as a basis for investigation of the nature of quantization of orbits, the interaction of the electron and nucleus in stable states and at transitions between discrete terms. «Frequency» hypothesis is chooses to find parameters of orbits. The characteristics of the electron motion corresponding to this hypothesis are compared in detail to the classical values. The differences are found for some orbits and it is shown that the classic version, due to several reasons, is not preferable. For the «frequency» hypothesis, the probable physical mechanisms are appearing which are responsible for the quantization of the energy levels and transitions between them. The limits of applicability of the fundamental laws of electrodynamics are discussed for scale of a single atom. The new hypothesis about the association of various types of interactions is continue to develop on the basis of wave mechanics of a continuous medium. Key words: Bohr’s model, the emission spectra, the radii of the orbits, the frequency the quantization levels, the excited states, the stability conditions, Coulomb’s law, wave mechanics. Contacts: E-mail: igolkins@gmail.com Pp. 14-24.