What Is Inside an Empty Bag?

A clear bag rests on a table after a grown-up takes out the last toy. You can see right through its crinkly sides. It looks like an empty bag, and soon you will discover what is inside.

Inside the bag is air, the invisible stuff all around you. Air has no colour for your eyes to see. It surrounds the table and the toys, and it is inside the open bag too.

When someone calls this bag empty, they mean it has no toys or other things they can see inside. The grown-up has taken the toys out, but air is still there. Invisible does not mean missing.

A toy takes up space, which means the room it takes up. A big toy needs more room inside a bag than a small toy. Air takes up space too, even though you cannot see it.

The grown-up holds the bag open, with no toys inside. Next, they will scoop up some room air and close the bag. Can you guess whether the closed bag will look flat or puffy?

The grown-up alone handles the bag, well away from faces. They gently sweep the open bag through the air, then close its opening tightly. Closing the opening keeps the air inside instead of letting it escape.

Now the bag looks puffy, like a little pillow without any stuffing. The air inside takes up space and keeps the sides apart. The bag shows a clue about air, but the air itself stays invisible.

An open cup with no drink in it contains air too. A roomy bag can even hold a toy and air together. The toy takes up some space, and air fills the gaps around it.

Air is invisible, and space is the room it takes up. The grown-up catches air in the bag and closes it, so the bag stays puffy. A bag that looks empty has air inside.

You have discovered a quiet little secret hiding inside an everyday bag.