In this paper we present an analysis of the responses of 8th grade students (13-14 years old) to a questionnaire post-test administered after a learning sequence about chemical reactions. The focus of the analysis is to identify ways of using and the appropriation of scientific language by the students. We use elements of functional grammar of Halliday and Martin to examine the compositional structure of texts. Such an analysis was made considering studies of the formation and evolution of concepts from Vigotsky's sociocultural approach, highlighting evidence of appropiation of the concepts of transformation, chemical elements and substances. The results indicate a variety of compositional styles, and a prevailing narrative explanation closer to everyday language. We conclude that the appropriation process is long and the thinking of students, despite having traces of consistency and objectivity, differs from conceptual thinking.
Chemistry teaching; Middle school; Scientific writing; Conceptual learning
