SUBMICROSCOPIC REPRESENTATIONS AS A TOOL FOR EVALUATING STUDENTS’ CHEMICAL CONCEPTIONS

Iztok Devetak,^a* Matej Urbančič,^a Katarina S. Wissiak Grm,^b Dušan Krnel,^a and Saša A. Glažar^a
a University of Ljubljana, Faculty of Education, Kardeljeva ploščad 16, 1000 Ljubljana, Slovenia
^b University of Ljubljana, Faculty of Natural Sciences and Engineering, Department of Chemical Education and Informatics , Vegova 4, 1000 Ljubljana, Slovenia

Abstract
The purpose of the research was to establish how successful the secondary school students who have chosen chemistry as part of their Matura exam and the first year university students are when working with basic chemical concepts concerning solutions, acids and bases as well as equilibria based on submicrorepresentations. In solving such tasks, the secondary school students with chemistry as part of their Matura exam achieved better results because in their preparation for the exam they worked with chemical concepts by linking three levels of chemical concepts (macro, submicro and symbolic level). This way of learning and teaching chemistry is rarely practised in our secondary schools. In order to reach higher cognitive levels, we would recommend that the three levels of understanding chemical concepts be linked to a greater extent.

Key words: submicroscopic representations, chemical concepts, evaluation, Matura exam.