Make a paper clip float on water. The paper clip is held afloat by the surface tension of the water. Water molecules are polar, so the molecules pull on each other. This creates a tension – like a thin, flexible membrane on the surface – which helps hold the paper clip afloat. The tissue paper allows you to lower the paper clip onto the water gently, without breaking the surface tension.
Insects such as water striders use water tension to appear to walk on water.
- A bowl
- Tissue paper
- A paper clip
- A pencil with an eraser on the end
Fill the bowl with water.
Tear off some tissue paper (around 4in x 2in).
Gently place the tissue paper onto the surface of the water so that it floats.
Place the dry paper clip on top of the tissue.
Use the rubber end of the pencil to carefully poke until the tissue sinks and the paper clip is left floating.