Basic Concepts of the Microworld in Czech Chemistry Textbooks for Lower Secondary Schools

Our text analyses how the concepts atom, molecule, element, and compound are initially introduced in nineteen Czech chemistry textbooks for lower secondary schools. We examine textbooks published between 1954 and 2022. The analysis focuses primarily on the demands these introductions place on students’ abstract thinking. The results show a gradual shift from older, less precise, and simpler definitions to more abstract, more recent definitions based on the particle model and proton number. This development is discussed in the context of science education research, which highlights students’ difficulties in working with the submicroscopic level and with models of atomic structure. The study points to a tension between the scientific accuracy of modern definitions and students’ current cognitive capacities. In addition, it draws attention to a partial discrepancy between official definitions and the terminology used in contemporary pedagogical and scientific literature.