Virtual and tactile molecular models: Their complementary nature in discovery-based general chemistry

CHED 216

Scott A. Sinex and Barbara A. Gage. Physical Sciences Department, Prince George's Community College, 301 Largo Road, Largo, MD 20774-2199
How do beginning students interpret the shape of molecules? Can they understand ideal and real geometries? Visualizing the geometries through the use of ball-and-stick molecular models plus interactive computer structures has given instructors and students a powerful edge in investigating simple to complicated molecular structures. Interactive software allows easy measurement of bond lengths, bond angles, and torsion angles. The multiple display modes permit viewing around and within molecules, plus the space-filled display mode gives a realistic idea of size. The strain and distortion of molecules can be “discovered” and many interactions predicted. The connections to biologically-important molecules and forces, such as H-bonding in DNA or proteins, can be easily made. We will illustrate how we have enriched topics and adopted a more molecular approach via guided-inquiry activities in first and second semester general chemistry. This includes using Spartan and interactive web pages with Chime. Both virtual and tactile molecular models have a large part to play in introductory chemistry. Electronic resources will be provided.