A metal cylinder holds helium gas at the gift shop. When someone orders a balloon, a small amount of helium is transferred from the tank to the balloon. Use kinetic molecular theory to explain why the helium gas expands to fill the balloon, and why liquid water and paper confetti would not behave in the same way.?

Gases are unlike other states of matter in that a gas expands to fill the shape and volume of its container. For a small amount of helium gas transferred from the tank to the balloon, the gas (helium) expands and fills up the entire mass of the balloon.

According to the kinetic theory, gases can also be compressed (that's the reason why the metal cylinder can hold the helium gas) so that a relatively large amount of gas can be forced into a small container.

The kinetic-molecular theory explains why gases are more compressible and expands more than either liquids or solids. Gases can expands to take the shape of the container in which they are in, unlike liquids and solids. This is responsible for in this case, why helium gas introduced to the balloon fills up the balloon.