This lecture discusses the estimation of the probability of different quanta levels in the vibrational degrees of freedom of ozone undergoing decomposition. The instructor presents a scenario where 40 quanta of energy excite the vibrational modes and guides through the calculation of the probability of having at least 10, 20, or 30 quanta in a specific vibration. Combinatorial analysis is used to derive the probabilities based on the nonlinear nature of ozone's molecule. Additionally, the lecture covers the application of transition-state theory to estimate rate constants in chemical reactions, focusing on the barrier height difference and vibrational wave numbers. Various scenarios and calculations are presented to illustrate the concepts.