Now includes both printable PDF and Google Slides versions!The PhET: Reactants, Products, and Leftovers Activity Guide is used along with the free *Next Generation PhET Simulation on Reactants, Products, and Leftovers. First, students will experiment with building sandwiches to see how the number of ingredients determines the number of sandwiches they can make. Then, students use the same concept to predict Reactants, Products, and Leftovers and to identify Limiting Reactants in chemical reactio