Contribuições da história da ciência para a ressignificação do conceito de quantidade de matéria e sua unidade de medida, mol

Abstract

The teaching of chemistry is permeated by content and many students have difficulties understanding them. This research aims to investigate one of the topics that need to be studied in the teaching and learning process of Chemistry: the Amount of Substance and its unit of measure, the mol. To do so, we did a historical reconstruction on the subject and approach the atomic concepts of John Dalton and the debate on the theme that defined decades after this the concept of the Avogadro. For the development of this subject in the context of the classroom, we delimit some historical episodes and their participants, beginning with the definition of atom by Dalton, and ending with the definition of the constant of Avogadro by Jean Perrin in 1909. At the same time, we seek to investigate the main causes besides the scientists factors that influenced the construction of the by Amount of substance concept. We have had the support of professors from the universities of Minas Gerais who, when they answered the questionnaire, enabled us to know the main conceptual difficulties of students in the initial stage of graduation; and also the strategies used by teachers to overcome such obstacles. We also carried out an analysis from the historical point of view in the didactic books indicated by the National Plan of the Didactic Book, from the years of 2015 and 2018, in order to evaluate how these works dealt with the theme; and, consequently, we have a panorama, even if partial, of the type of information that the students have about Quantity of Matter upon entering the University. As a last step of the research, we proposed and applied a didactic strategy with Licentiates in Chemistry of the Federal University of Juiz de Fora. For this stage, we performed the intervention in two classes, one in the initial phase of the course, and the other in the completion phase. Our didactic strategy sought to value the History of Science so that the licenciandos could resignify the concept of Quantity of Matter. We believe that this can be an excellent didactic resource in the Teaching of Chemistry, because from the historical contextualization it is possible for the student to re-significate concepts, thus minimizing the routine activity of memorization. Through the different didactic interventions used with beginning and finishing students, it was possible to ascertain the didactic utilization coming from the teaching strategy proposed in this study.