ADHESION , COHESION, SURFACE TENSION:

1. Drop the Clip :  A paper clip on the surface of water will float but if you add a drop of soap in water it sinks because the soap breaks the surface tension of water.
2. Soap Powered Paper Boat: A paper water boat can be made to move in water using soap drops as it will break the surface tension and water molecules force the boat to move.
3. Do Not Open: When we make holes in a plastic bottle full of water, the water does not drip out as surface tension holds the water but if we open the cap of the bottle, air pressure from top makes the water drip.
4. Poke Me Not: In a plastic bag full of water, many pencils can be put through without making the water drip because of the same phenomenon.
5. Milk Rainbow: When we add some food colour drops in milk and add soap, the milk molecules move around making the colour spread and giving rainbow like effect.
6. Poke the Pepper: When we add a drop of soap in a water bowl filled with pepper, the pepper moves around because the surface tension of the water breaks.
7. Terry Triangle: The same happens when we make a shape using some toothpicks in water, on adding soap, the toothpicks move around.