Aprendizagem significativa no ensino de química : uma proposta de unidade de ensino sobre número de oxidação

Abstract

This work aims to present the construction, application and evaluation of a potentially significant teaching unit (LIFO) in the Chemistry curricular component in a first year high school class of a state school in Caxias do Sul. This research is based on Ausubel's Significant Learning Theory. The selection of the Oxidation Number content was done observing the school's study plan, as this is one of the units worked in the mentioned series. The choice of the series was based on the fact that, out of the three high school grades, it is the one with the highest failure rate, indicating, therefore, greater difficulty in learning. The choice of the topic, Oxidation Number, was made to propose a way of working on this subject in a contextualized way and with diversified resources, taking into account that, according to Neto and Collaborators (2008), one of the main reasons for the fact that students have a great difficulty in learning Chemistry occurs because, mostly, the contents are worked without contextualization and use of diversified resources. Analyzing this context, a LIFO was proposed and applied, involving an approach that started with questionnaires and texts with survey activities, after the presentation of the topic and the problem with the use of visual resources, the resolution of activities involving problem situations were developed with the use of a didactic material, created by the class regent for this unit and, finally, applied summative evaluation. Therefore, the unit analysis involved diagnostic and summative evaluation, and these data were tracked throughout the development of the work and students' descriptive material was collected. As a result of the present Teaching Unit, it was possible to conclude that it was successful, since the teenagers involved, at all times, presented a predisposition to the proposed activities, performing them with motivation, which referred to productive mediation by the teacher. In addition, at the end of the Unit, it was possible to record that they developed the expected skills in the construction of knowledge in an active way, since they applied the same in other contexts. As a product of this work, a didactic guide of this UEPS was organized, in addition to the didactic resource developed, which consists of a board to solve the problem situations on Oxidation Number. These materials can be used by other teachers both for teaching this unit and for reviewing in the case of the following series.