This paper attempts to show one of the ways history of chemistry can be teachable for chemistry teachers, it means something more than an undifferentiated mass of names and dates, establishing a temporal framework based on chemical entities that all students use. Represents a difficult equilibrium between over-simplification versus over-elaboration. Hence, following the initial proposal of Jensen ("J Chem Educ" 75:679-687, 817-828, 961-969, 1998), reconstructs the history of one of chemistry dimensions (composition-structure) in terms of three revolutionary moments. These moments are considered in terms of the Kuhnian notion of "exemplar," rather than "paradigm." This approach enables the incorporation of instruments, as well as concepts into the revolutionary process and provides a more adequate representation of such periods of development and consolidation. These three revolutions are called by the chemical structural entities that emerged from the same: atoms (1766-1808); molecules and isomers (1831-1860); electrons and isotopes (1897-1923).