Li's balloons

This task is about air pressure.
balloon for Li's balloon item.png

Uncle Chan blew up a balloon for his nephew, Li. He tied the neck of the balloon, and gave it to him to play with.

Question

a)  Is the air pressure inside the balloon greater, less or the same as the pressure outside?

    • greater

    • less 

    • the same as

Question 2Change answer

b)  When Li threw the balloon into the air, it fell slowly back to the floor.
     Li remembered that the helium balloon he bought at the school gala the week before
     had floated up to the ceiling and stayed there.
     Why do helium balloons float more easily?

Question 2Change answer

c)  Li was rough with the balloon and it finally "popped".
     Explain what made the noise when the balloon "popped".