Atomic theory is a common topic throughout any introductory chemistry course. It is likely that Rutherford’s gold foil experiment gets at least some attention in your course. I have used a simple activity that gives students an opportunity to replicate Rutherford’s experiment through an analogy experiment that may allow for easier conceptualization of the experiment itself and provide additional support for model development.
Trends related to placement of elements on the periodic table are often taught using diagrams in a textbook. Students often memorize trends, but to get a true grasp of their meaning and what causes certain patterns is best understood when students create their own models and discuss the patterns with others.
In this age of scientific inquiry, molecular modeling, digital classrooms, and differentiation, I felt downright guilty about any teacher-centered time. My classroom is flipped after all. I’m not supposed to be lecturing, right?