Evaluation of mental models of prospective science teachers on chemical reactions

Abstract

The aim of this study is to examine prospective science teachers' (PSTs) mental models and meanings for the concept of chemical reaction. For this purpose, this study adopted a phenomenological research design including 48 PSTs. To determine the mental modeling about chemical reactions, PSTs were given an interview card showing the reaction between magnesium and oxygen gas, and were asked to draw and visualize this reaction and a semi-structured interview was held about the specified reaction. The results revealed that the majority of the PSTs used the particle atom model to model for the chemical reactions, and as their education level increased, the models they used shifted from the particle model to the atomic model. In addition, the explanations showed that all the PSTs explained the reaction of magnesium with oxygen gas at the macroscopic level in the first stage and when asked the evocative interview question, most of them explained the reaction at the microscopic level, but some PSTs continued to make explanations at the macroscopic level despite the hinted interview problem. It was also found that the transition from the macroscopic level to the microscopic level of the PSTs’ explanations with the evocative interview question was influenced by the education level and their mental models regarding the reaction. In chemistry teaching starting from the high school senior year, it is recommended to use visual materials related to reactions based on atomic models instead of particle-based materials.