Question

A student takes a balloon and fills it with air. What will happen to its mass

Answer 1

Gases, such as the air or helium inside a balloon, take the shape of the containers they're in. They spread out so that the space is filled up evenly with gas molecules. The gas molecules are not connected.

Air can also contain solid particles such as dust and liquids such as water droplets. Students will conclude that air is matter and therefore has mass and takes up space.