Thread Loop Opens with Soap

Loop snaps open into a larger shape. Ask students to predict what will happen. Float loop, touch soap inside loop. Key idea: Soap lowers tension inside; higher tension outside pulls the loop outward. Ask: What is pulling the thread? Safety and cleanup: Fresh water; wipe spills. https://www.google.com/search?q=%22Thread+Loop+Opens+with+Soap%22+science+demonstration+experiment