A few dry paper clips
A large tissue paper
A bowl of water
A pencil with an eraser attached to its end
A pair of scissors
Place the bowl of water on a table.
Put a paper clip into the bowl. You will notice that it sinks. Remove the paper clip out of the bowl of water.
Gently cut the tissue paper into a square which is slightly larger than the paper clip.
Place the tissue paper into the bowl of water. You will notice the tissue paper will start floating.
Carefully place the paper clip on the tissue paper. Make sure the paper clip does not touch the surface area of the water.
Now gently use the eraser end of the pencil to poke the tissue paper (not the paper clip) until the tissue sinks. You will notice that the tissue sinks but the paper clip remains floating on the surface of the water!
How does this happen?
This simple yet amazing experiment works on surface tension. Surface tension is a thin sheet or skin formed by water when it placed still for a long time. Surface tension tightly holds the water molecules together. Thus, if the surface tension of the water remains undisturbed, it will be able to support the paper clip. Thus, the paper clip is not actually floating, it is simply being held on the water surface due to surface tension. Several insects such as grasshoppers use this “sheet” or skin to walk across water.