Mom : How does the cloud feel? heavy or light? soft or hard?

Let the child to place the "cloud" (cotton ball) gently over the cold water. 

Explain that water that has evaporated has traveled up to the cloud and it is a lot colder up in the sky,

so the vapor turns into water, and it is filling up the cloud. 

Mom :: Can you see the "cloud" filling up with the water? 

Mom : Let's pick up the "cloud" (cotton ball) from the pan. 

Mom :  How does the "cloud" feel now? 

             Light or heavy?

             Warm or cold? 

             What is happening with the water? 

Kid  : water is dripping from the "cloud".

Mom : why?

KID : The cloud cannot hold all that water, is too, too, heavy. 

Mom : What do we call when water falls  from the clouds because they are too heavy with water? 

KID : Rain!  It is raining!

Mom : Yes, you are right, 

         And what happens to the water?