this is true because The mass of the warm balloon is the same as the mass in the cold balloon. In the warm balloon, the gas molecules are free of each other and moving rapidly because of all the energy they have. They collide with each other and with the wall of the balloon exerting pressure, which gives the balloon its size (volume). As the balloon cools in the cooler (freezer), the air molecules transfer energy to the surrounding cooler (freezer). The molecules of air are still free of each other but they do not move as rapidly or as far apart and their collisions with the balloon walls are not as forceful. As a result the volume of the balloon containing the cool air decreases. Heat and cool only speed up or slow down the motion of the molecules. When the balloon was heated with the flame the molecules where moving so much that they transferred their heat and energy to the balloon walls causing it to pop.
