This study is a systematic literature review on the role of models and representations in the teaching, learning and understanding of the atom and atomic concepts. The aim of the study is to investigate the role of different visual representations, what models and representations are used in the science classroom, how learners interpret different external representations of the atom, what mental models students construct, and how the representations can be used and designed for meaningful learning and teaching of the atom and atomic concepts.   In this systematic literature review, a combination of different databases was used to search for literature, namely ERIC, Scopus and Google Scholar. Some limiters were used to narrow down the returned results: the articles should be peer-reviewed and be published 1990-01-01 or later. Ten of the returned articles were included for individual analysis in the study.   The results of the study show that students often find concepts of atomic structure difficult and confusing. The abstract microscopic world of atoms cannot be seen with the naked eye, and models are therefore necessary and crucial educational tools for teaching atomic concepts in school. However, when using a model, it is important for the teacher to explain the rules of the model, and the advantages and limitations of the representation must be discussed. Analysis of the included articles revealed three types of representations used to represent atomic phenomena: two-dimensional static diagrams or pictures (e.g. a picture of the atom), three-dimensional videos or simulations (e.g. virtual reality simulations), and visual analogies (e.g. the Bohr planetary model of the atom). The use of simulations and interactive learning environments seem to have a positive effect on students’ learning. One of the studies, described in the articles included for analysis, showed that students appreciated the use of virtual reality simulations, since it made abstract concepts easier to understand when they could be visualized.

This report presents the results from a survey study on Swedish upper secondary school physics andchemistry teachers’ use of models and representations in teaching the atom. The study builds upon an earlier systematic international literature review on the role of models and representations in the teaching, learning and understanding of the atom. The overall aim of the study is to explore what models and representations are used by Swedish upper secondary school physics and chemistry teachers in their teaching about the atom, what informs teachers’ selection of the atomic models and representation forms and how they specifically use them in their teaching of the atom. The method for collecting the data for this study was an electronic questionnaire containing six introductory questions followed by nine open and four closed items, which were analysed both quantitatively and qualitatively. Thirty-one responses were received and analysed in this study. The results of the study indicate that Swedish teachers’ selection and use of atomic models and representation forms in their practice correspond with findings in the previously conducted literature review. For example, the Bohr atomic model was shown to be the most popular for teaching about the atom amongst the Swedish teachers in this study, since it is deemed intuitive and easy to visualize. A further result revealed that the de Broglie atomic model was only used by physics teachers, and that physics teachers overall used more atomic models in their teaching than chemistry teachers, a finding that might be related to the different teaching content in physics and chemistry. The study also shows that Swedish teachers are very comfortable with, and advocate, using different representation forms in their teaching. One interesting finding in this regard was that the use of physical models is predominantly more popular among chemistry than physics teachers. In line with the findings in the previous literature review study, students’ prior knowledge and individual learning styles were found tobe important influencing factors in teachers’ selection of representation forms to use in the classroom.The majority of the teachers also agreed on that it is important to explain to students how models should be interpreted and used, but one interesting finding, that differs from the previous research, is that some teachers were of the opinion that students have an already well-developed modelling ability when encountering different models of the atom.