P39: NGSS in middle school: Causal thinking about molecules and matter
Many misconceptions in chemistry persist because students apply a familiar and intuitive linear causal model when a more complex nonlinear model is needed. This session will discuss the design and results of three middle school lessons that pair the NGSS cross-cutting concept of cause and effect mechanisms with the practice of constructing explanations from evidence within core concepts about the structure and properties of matter. The lessons begin with a macroscopic introduction to matter and volume and progress to the creation of particulate level models that students revise, defend, and use to make predictions about phase changes at different temperatures. Student examples from a variety of middle school groups, including English learners, will be shared. Formative assessments guided by the Developing Assessments for the Next Generation Science Standards (National Academies Press) will be also be shared. These lessons were designed to align closely with the practices, cross-cutting concepts, and core ideas of the NGSS. As a result, lessons help students talk about and develop non-intuitive and nonlinear ways of thinking about scientific processes in order to challenge persistent misconceptions.