Answer:
 Example 1:
 What happens when I blow hot air on the balloon? Why?
 What is happening to the air inside the balloon?
 What do you think would happen if the balloon was placed in a cold car?
 What would happen to the balloon as the temperature increases in the car? Why?
 Ask the students to think about what might happen to a balloon in a bottle when it is heated.
Example 2: 
 Water is placed in the freezer.
 Ice melts.
 A puddle evaporates.
 
Explanation: