Diatomic molecules: Connect two gumdrops with one toothpick. Ihis geometry 15 called linear and is similar to any diatomic molecule, such as oxygen (0,). Ammonia: Using the tetrahedron you built in step 1. Remove one gumdrop and toothpick from the outside . This is the shape of ammonia , and its geometry is called trigonal pyramidal. Water: Still using the altered tetrahedron from step 5. Remove one more gumdrop and toothpick from the outside . This is the shape of water, and its geometry is called bent. Take a photo of this and submit in the lab quiz