Recent years changes have taken place in European and Swedish schools. The classroom situation has in many schools changed from single-lingual to multilingual. A larger number of students in Sweden are in the beginning of speaking Swedish but who participate in the same teaching as native speakers. The science disciplines, primarily chemistry, are experienced as difficult by many students because chemistry is abstract and contain many subject-specific concepts. It is a great challenge for teachers to offer teaching adapted to all students regardless of first language.

This study intends to investigate how a student-active approach to representations and models in chemistry might be a way to develop the scientific language of second language learners. Active student approach to  properties of polymers is a concrete way to visualize and discuss chemical bonding, often perceived abstract otherwise. The study is conducted in a multilingual class, with eight different first languages represented, in upper secondary school in Sweden. The teacher and majority of the students speak Swedish as their first language. Since several languages are represented students cannot use code switching or translanguaging when learning chemistry, to the same extent as in bilingual contexts. In this study, learning is approached as a sociocultural activity focusing on how scientific language develop through interaction with others. Data is collected from classroom practices using audio and video recordings and followed up with semi-structured interviews. Language is analysed from the perspective of adequate scientific language and correct use and understanding of subject-specific concepts using a thematic coding approach. To increase validity intra-rater reliability are used. As the amount of research on how second-language learners use subject specific language while working with models and representations in chemistry is limited, this study might provide useful information about new strategies to improve scientific language of second language learners.