Petra and Huy are doing a class demonstration to show that solids, liquids, and gases all have mass. They use a balance for the solids and the liquids. They wondered if gases have mass. Which is the best way for them to show that air has mass?

Use a fan to make a current of air.

Compare the masses of two inflated balloons.

Heat water to show it changing to water vapor.

Compare the masses of an inflated and empty balloon.