Introducing the concept of oscillator strength in the initial quantum mechanics courses

Abstract In this paper, a sum rule for electron transitions between atomic states, proposed by Thomas, Reiche and Kuhn (TRK), presented only, and at most, in advanced courses, is examined in a didactic way for the case of transitions between states of electrons in two familiar systems, the one-dimensional finite and infinite potential wells, traditionally studied in introductory disciplines of quantum mechanics in undergraduate physics courses.