This paper reports on model-based teaching and collaborative inquiry learning of chemical processes and physical phenomena related to socio-scientific issues (SSI) in Swedish preschools (1-5 years). A special focus is children's learning related to intended and enacted teaching, and the research contrasts teaching and learning processes with and without scaffolding by tablets. A developed theoretical framework for analysis of different referential meanings experienced during work with chemistry and physics in preschool will be presented. Results describe in detail how reasoning and questioning during teaching engage children and preschool teachers. The role of tablets in collaborative physics learning will be discussed.