A Comparison of University Lecturers' and Pre-service Teachers' Understanding of a Chemical Reaction at the Particulate Level

Abstract

This study identified a number of views prevalent among two groups of teachers about a single chemical reaction. Teachers' views were identified on the basis of the diagrammatic representations of particles that they made about the combustion of magnesium in air. Two major differences were identified between the university lecturers' and student teachers' views. According to university lecturers, in general, intermediates form between the reactants of magnesium and oxygen gas, whereas in the view of half of the pre-service teachers, the reactants form free particles before forming magnesium oxide. Many pre-service teachers held a view of loosely packed magnesium oxide, a scientifically invalid position. While training future teachers, more attention should be paid to the "atomic" level of chemical description and its associations with the macro and symbolic levels.