Chewing Gum and pH Level of the Mouth: A Model-based Inquiry Sequence to Promote Scientific Practices

Abstract

Television ads usually use scientific messages to highlight the benefits of the products they advertise. This is the case of a known brand of chewing gum that “helps to increase the oral pH after meals”. From this starting point, we have developed a short sequence of activities (sensopills for 1.5h) with a Model-Based Inquiry teaching approach to engage students in scientific practices, and understand disciplinary core ideas and crosscutting concepts in order to promote critical consumers of information about science, as NRC recommend. We use a historical acid/base model (Lemery) to explain and predict oral pH phenomena. The sensopill “chewing gum” has been implemented with hundreds of secondary school students. Learning self-regulation results show that students recognized having learned the difference between dilution and neutralization and the concept of pH and their improvement at some scientific inquiry skills such as hypothesis formulation and data collection.