Interlocking toy building blocks (e.g., Lego) as chemistry teaching modules are presented. Interlocking building blocks were assembled on a baseplate to depict chemistry concepts of Lewis structures, chemical bonding, conjugate acid-base pairs, types of chemical reactions, irregularity in ionization energy trends, and the decay of a radioactive isotope. The modules were presented to visualize these chemical concepts in undergraduate introductory and general chemistry classrooms. Modules were presented on a document camera in an online mode of delivery.