Science education often relies on external representations to provide tangible, working models from which students can construct, evaluate, and revise their internal representations (metal models) of abstract, non-experiential scientific phenomena. External representations range from static diagrams to dynamic animations, from simplistic, stylized illustrations to more complex, realistic presentations. However, prior research has shown that, while potentially beneficial, external representations can also lead to development or strengthening of alternative student conceptions. This interactive workshop will explore the educational literature on chemical representations and misconceptions, connections with NGSS, and implications for learning and teaching in K-12 classrooms. K-12 teacher participants will be encouraged to collaborate within working groups to construct and revise pedagogical materials and strategies. Please register here: https://www.surveymonkey.com/r/ACS_K12_TeacherWorkshop