How does the pedagogical content knowledge of elementary teachers with different years of experience vary as they teach chemical reactions

The purpose of this study was to investigate the effect of teaching experience on elementary science teachers? pedagogical content knowledge about chemical reactions. A case study method was utilized in the study. Participants were six elementary science teachers who had different teaching experience in teaching science. Of the participants, two participants were teaching first time the topic `chemical reactions?. The other four participants had two and four years of teaching experience on the teaching of chemical reactions. Data sources included classroom observations, interviews, and researcher?s field notes. Data were analyzed using Hyper Research program and used the content analysis method.Findings indicated that the teaching experience made positive effect on the teachers? pedagogical content knowledge about chemical reactions. Findings also indicated that the teachers who had teaching experience on the teaching of chemical reactions had more developed pedagogical content knowledge than the beginning teachers who were teaching first time the topic. Furthermore, it was found that all the six teachers hold constructivist teaching orientations. In addition, the orientations teachers hold affected knowledge of instructional strategies, knowledge of students, and knowledge of curriculum. While all of the teachers had used a number of representations and instructional strategies, especially teachers have teaching experience used a more sophisticated implementation of representations and instructional strategies. Experienced teachers did have a high level of knowledge in predicting students difficulties associated with the topic. In addition, all of the teachers had used similar assessment methods in revealing students? misconceptions and in assessing students? learning. In light of the findings obtained implications for teacher education and policy are made.