Pencils Through a Water Bag

Very little water leaks out. Ask students to predict what will happen. Push pencils straight through both sides of the filled bag. Key idea: Flexible plastic polymer chains stretch and seal around the pencil. Ask: Why doesn't the hole stay open? Safety and cleanup: Teacher inserts pencils over tray. https://www.acs.org/education/whatischemistry/adventures-in-chemistry/experiments/poke-dont-soak.html