This paper describes an analysis of teaching instances that are part of an in-service preschool teachers programme. The overall aim of the project is – together with teachers – to study model-based teaching and collaborative inquiry learning of chemical processes and physical phenomena in preschool. Our interest is directed towards the teaching of science in preschool, with particular focus on use of digital tools and the verbal communication and intersubjectivity established, or not established, between teachers and children during learning situations in preschool. Teaching activities were jointly developed by work teams in preschools and researchers. A qualitative analysis of video recordings of enacted teaching activities has been performed. The focus was excerpts representing qualitative differences in intersubjectivity related to the object of learning, and what characterised the communication in these situations – the roles of teacher, children and scaffolding digital technology. The focus of this report will be teaching activities developed  with air resistance as the object of learning. The result indicates the importance of intermediary objects of learning and place them on the science teaching agenda indicating that they can constitute a supporting element in the conquest of new knowledge. Further, children’s understanding of abstractions and physics concepts when designing a digital movie about investigated phenomena is discussed. The three-year professional development (PD) programme is ongoing and analysis of several instances during the first and second years will be discussed at the conference.