Secondary School Science Teachers' Perceptions about the Mixing Phenomenon Related to Dissolution and Diffusion

The aim of this study was to research the characteristics of science teachers' thinking related to dissolution and diffusion. For this study, five science teachers who majored in chemistry or chemistry education were selected and interviewed. These teachers have been teaching on average for 2-6 years. From the study, it was discovered that the science teachers didn't recognize the necessity of sorting out diffusion from dissolution. The teachers divided in various mixing phenomena with diverse criteria. The science teachers had difficulty in sorting out diffusion from dissolution based on solubility and Gibbs' energy. The teachers didn't see the linkage between the contents that were divided into chapters, and didn't find omitted contents themselves in the chapters that introduced applicable principles. During the interviews, the teachers felt the need to understand the principles for understanding phenomena. But they did not have the ability to teach these principles after learning about the principles themselves. Therefore, it is necessary to develop teacher education programs, as well as a science curriculum, that helps in linking the knowledge between natural phenomena and principles.