At home for 5-11 11-14
What you need
- A paperclip
- A cereal bowl
- Washing-up liquid
- A tissue
- Put the paperclip on a flat piece of tissue in the empty bowl.
- Fill the bowl with water, being careful not to pour water directly on top of the paperclip and tissue.
- The tissue will sink as it absorbs water, but the paperclip will float! Now put a drop of washing-up liquid in the bowl. The paperclip will sink!
Results and Explanation
Though the paperclip should be heavy enough to sink, the surface tension of the water holds it up. When the washing-up liquid dissolves in the water it lowers the overall surface tension, so the paperclip sinks.
These experiments have not been specifically safety tested for home use but we believe them to be safe if the instructions are followed. Adult supervision or direction is recommended as appropriate. All experiments are carried out at your own risk.