This work explores both molecular reaction dynamics and chemical kinetics, and their respective theories. The topics discussed include interaction potentials; relative motion and the collisional approach for chemical reaction in the gas phase; partition functions; transition state theory; unimolecular reactions; molecular reactions calculations; non-adiabatic transitions; surface kinetics; chemical reactions in solution; energetic changes in solvating a molecule; transition state theory in solution; models for diffusion; Kramer's theory of viscosity of solvent in chemical reactions; and...