Fill a transparent glass of water. Fill it as much as possible. Allow the children to pour water in to the glass. Let the children feel that the glass is totally full. Now take an ink filler. With the help of ink filler, try to add s of water to the glass of water. Let the children observe and count the number of water s added using the ink filler. Show them the spherical surface of water as it is being ped. So, now even after filling the glass fully, there are space to add few more s. This is due to surface tension of water which will try to keep the molecules as much close as possible. This property of surface tension of water helps it to take the spherical shape. Now using a pin or a pencil pierce the water on top. Observe the water spilling out of the glass. The same experiment can be done using a coin(2 Rs. coin). This is a simple water activity experiment which teaches the kids of kindergarten about the surface tension of water.