Una secuencia de enseñanza/aprendizaje para los conceptos de sustancia y reacción química con base en la Naturaleza de la Ciencia y la Tecnología

Inside the international research project Teaching and Learning about Nature of Science and Technology: An experimental and longitudinal research (EANCyT, acronym in Spanish), a teaching/learning sequence is described, which has been designed to improve the comprehension of the Nature Of Science (nos) and Technology, trying to help students of the General Chemistry course in Undergraduate Education to learn adequate ideas around the scientific competences of «defining» and «modeling». This sequence involves students in an inquiry process related with the history and the definitions of the concepts «substance» and «chemical reaction», two of greatest importance in any chemistry course. Throughout the sequence, students will gradually improve the definitions of these two concepts from the macroscopic level to the nanoscopic one, trying them to be convinced that “defining is modeling”. The students will face the reading of essays on historical and experimental facets of both concepts. Additionally, it is analyzed here the carrying out of the sequence with a group of students on the first semester of 2012, and the changes that were done after this evaluation.