eng Science and Education Publishing World Journal of Chemical Education 2375-1657 2018-04-16 6 2 102 106 10.12691/wjce-6-2-5 WJCE2018625 article Daniel J. Swartling dswart@tntech.edu 1 Janet G. Coonce 1 Derek J. Cashman 1 Department of Chemistry, Tennessee Tech University, 55 University Drive, Cookeville, TN 38505 United States Large-scale molecular orbital balloon models have been designed and developed for implementation in the general, organic, or physical chemistry classroom. The purposes of the models are to help students visualize and understand concepts of pi-bonding, conjugation, aromaticity, and cycloaddition reactions or symmetry-controlled reactions. Second-semester organic chemistry students have welcomed the models with positive responses, claiming that the 3D models bring 2D textbook and lecture images to life. The balloon models may be constructed and presented by the instructor during a formal lecture, or they may be constructed by students during problem-solving workshops. Short video tutorials have been created to demonstrate the construction of these inexpensive classroom manipulatives. http://pubs.sciepub.com/wjce/6/2/5/wjce-6-2-5.pdf High School / Introductory Chemistry First-Year Undergraduate / General Second-Year Undergraduate Upper-Division Undergraduate Demonstration Organic Chemistry Collaborative/Cooperative learning Computer-Based Learning Hands-On Learning/Manipulatives Alkenes Alkynes Aromatic Compounds MO Theory