A good example of surface tension.
Things Required:
Cup and saucer
Paper clips
Eye-dropper
Directions:
Set the cup in the saucer. Fill the cup so that it may overflow with water. Continue to add water with the eye-dropper until one drop causes the water to spill over the rim. Drop one paper clip at a time into the cup until the water spills over the edge. Note: Before the water spills over, look at the surface of the water from the side.
This Is What Happens:
The water rises above the rim of the cup. The height of the water continues to rise as the paper clips are added. The water finally spills over the rim.
Science Behind It:
Water molecules across the surface are attracted to one another. This attraction is strong enough to allow the water to rise above the top of the cup without spilling. The bulge of water above the rim finally gets so high that the molecules of water can no longer hold together, and over the rim they go.
