Like the first activity, you should have seen the water bulging on the top of the coin. This is also caused by the cohesion of water molecules and also (like the cup in the first activity) the property that allows water to form a "skin" on its surface. This property is also the reason why some insects can walk on the surface of water without breaking the surface. What is this property?
Covalent bonds
Heat capacity
Adhesion
Surface Tension