Design of a didactical resource to introduce chemical formulas in secondary school

Abstract

• This paper presents the research conducted to create a history-of-science-based resource that would introduce students to chemical formulas in secondary education in France. This elaboration is based on theoretical frameworks dealing with educational reconstruction of teaching-learning sequences and on the analysis of teaching practices. Preliminary empirical investigations conducted with students and some teachers show the need to articulate the registers of models, reality and language at the submicroscopic and macroscopic levels for learning the concepts of chemical change and chemical reaction. The first part of the resource is implemented in the classroom. The second part that allows to write the reasons justifying the chemical formulas is rejected by two teachers. This leads to a first proposal of the evolution of the resource.