A balloon filled with helium gas floats in a big closed jar which is connected to an evacuating pump. What will be your observation, if air from jar is pumped out ? Explain your answer.
The balloon will expand due to there being greater pressure inside the balloon than outside as air is removed from the jar. But, this is under the assumption that the balloon has not been filled to full capacity. If the balloon has reached its full size before the jar has been completely emptied of air, removing more air (and pressure) from the jar will cause the balloon to burst.