You will need:
- Drinking glass
- Water
- Tissue paper
- Needle
Create some magic with a needle and be a master of scientific techniques.
INSTRUCTIONS.
- Fill a glass to the brim with water. Do this slowly so that it may not spill over.
- Wait for a minute, and then tear the tissue paper into a thin square which is slightly larger than the needle.
- Placing the needle on the tissue paper, lower both the tissue paper and the needle onto the surface of the water.
- The tissue paper will gradually begin to sink. Do not make any jerky movements or shake the glass.
- Wait patiently for the tissue paper to sink to the bottom. What has happened with the needle?
RESULT
Even though it is heavier and denser than water, the needle will be floating on the surface of the water due to surface tension, which basically is a result of water molecules pulling inwards making the surface as tight as possible. When the needle is placed gently on the water with the help of the tissue, the weight of the needle pushes the water surface downwards. But the surface tension is pulling upwards from the sides, making the water push the needle upwards. If you touch the needle the surface tension breaks and the needle will sink.
