Question

A student observes that a paper clip floats on water in a cup even though the paper clip is denser than water. When the student mixes a drop of dish detergent into the water, the paper clip sinks to the bottom of the cup. What explains these observations?

Answer 1

This explains that surface tension of water is decreased due to mixing of detergent in it

Step-by-step explanation:

The clip is denser than the water but still it can float inside water then it is due to the phenomenon of surface tension of the water

As we know that water apply buoyancy force on the clip but since the density of clip is more so buoyancy force will not able to balance the weight of the clip, still the clip is floating in water due to the force of surface tension of water.

Now when we add detergent in the water then due to the action of detergent the surface tension of water will decrease. Now the weight of the clip is balanced by Surface tension of the water with detergent and buoyancy force both.

Since the surface tension is decreased now so we can say that the clip is not able to balanced now and it will sink down in the water.