Vacuum in a Radish

Equipment Needed

1 Knife
1 Radish
1 Saucer

The Experiment

Cut a large, firm radish in half with a single stroke of the knife (Fig. 1).

Use the point of the knife to scoop out some of the flesh of the radish in the half with the long root (Fig. 2).

Now press that half of the radish firmly into the center of a clean saucer (Fig. 3).

Lift the radish by its root (Fig 4).

The radish will stick so tightly to the saucer that you will lift the saucer along with the radish.

How It Works

When you scoop out the flesh from the radish, air fills up the space left behind.

This air is expelled when you press the radish against the saucer, creating a vacuum in the centre of the radish.

When you remove the pressure, air tries to enter the vacuum.

However, the surface of the radish and the saucer are joined together with an airtight seal, so air cannot enter the radish.

Therefore, the air presses down on the outer surface of the radish, causing the radish to adhere to the saucer.