I designed a full day of structured demonstrations, scaffolded so that each phenomenon presented to the students built upon the previous ones. In this progression, students could alter or extend their models of charge interactions. Similarly, these whole-class demonstrations provided students with repeated, collaborative opportunities to explain electrostatic phenomena with intentional use of the following academic vocabulary: positive charge, negative charge, net charge, attraction, and repulsion. Students were expected to construct explanations grounded in the charge models constructed using their observational data. Student explanations were conceptually clear, but I noticed inconsistencies in their academic vocabulary. As the demonstrations progressed, I prompted students to focus on their peers' explanations; I would then prompt students to “add on” to what was being explained or “change a word” to make an explanation more rigorous. Developing vocabulary became a shared experience between me and the students. By the end of the experience, students were constructing complex, interconnected models of charge interactions and developing their linguistic skills to accurately demonstrate understanding.