PURPOSE: To demonstrate surface tension in a perhaps counterintuitive way using soap bubbles.

DESCRIPTION: Pour some soap solution into the small glass lid of the soap solution container. Turn the valve so that only one side is connected to the hose, dip that end into the solution and blow a bubble. Rotate the nozzle so that the other side is connected and blow a bubble of a different size. Rotate the valve so that air can flow from one to the other. Q: What will happen to the two bubbles when they are connected? A: The smaller bubble will get even smaller and the bigger bubble will get even bigger.

SUGGESTIONS: This is a sensitive demonstration! Bubbles may easily burst.

REFERENCES: (PIRA 2A10.50) See also demonstration F3-02: SURFACE TENSION BALLOONS.

EQUIPMENT: Y tubes with clamps, bubble solution.

SETUP TIME: 5 min.

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