A Didactic Proposal for Addressing the Nature of Chemistry in the Context of Teaching Chemical Bonding in Secondary Education
Chemistry Education, Chemical Bonding, Nature of Chemistry
This study investigates the contributions of a didactic proposal grounded in aspects of the Nature of Chemistry, the role of scientific models, and the articulation of macroscopic, submicroscopic, and symbolic levels in the teaching of ionic bonding at the secondary school level. The research is being conducted with a second-year secondary school class at a public school in the municipality of Goianinha, Rio Grande do Norte, Brazil. For the present version of the dissertation, only data obtained from an initial questionnaire administered to 15 students are presented and analyzed. The instrument consisted of four open-ended questions addressing students’ conceptions of chemical bonding, the reasons attributed to the union of atoms, the representation of ionic bonding, and the particulate structure of a sodium chloride crystal. Students’ responses were qualitatively analyzed in dialogue with Textual Discourse Analysis and theoretical frameworks from studies on the Nature of Chemistry. Preliminary findings indicate substantial conceptual heterogeneity, with the greatest difficulties occurring in tasks requiring submicroscopic representation and explanation, particularly those involving the modeling of ionic bonding and the crystal structure of NaCl. The data also reveal recurring conceptions of bonding as a simple union of atoms, stability understood in teleological terms, and NaCl interpreted as an isolated molecular unit. These findings provide a baseline for the development of the didactic sequence and support an emphasis on ion formation, electrostatic interactions, crystal lattices, multiple representations, and the model-based nature of chemical knowledge.