Abstract <p>The analysis of the possibility of correlating the momenta and coordinates of a quantum oscillator using the Robertson–Schrödinger generalization formalism and the probabilistic concept of quantum mechanics has been continued. A detailed numerical study of the quantum oscillator excitation modes under a classical impact with variable frequency is performed. An analysis of the harmonic dependence of the quantum oscillator energy showed that the oscillator has frequency intervals of parametric instability, in which the oscillation amplitudes grow exponentially. The mean energy also increases, undergoing small oscillations, which are barely noticeable in resonance, and the correlation coefficient oscillates near zero level. The probabilities of leaving the ground state and passing to the second excited state are calculated for the oscillator. The penetrability of quantum tunnel barriers of moderate depth is estimated. It is shown that the increase in the barrier penetrability upon parametric excitation at the resonant frequency may be two to three orders of magnitude higher than at a detuned frequency. The mechanisms of the radical reactions leading to the formation of reactive oxygen species in an aqueous solution under a classical impact are developed. The use of measurable probabilistic representations for describing the states of quantum particles is substantiated.</p>