Keep a Paper Towel Dry Under Water

Materials:

• Large Container

• Enough water to fill the container high enough that you can completely submerge the glass in it

• Cup

• Paper Towel

Experiment Setup – Start with some observations about the paper towel.

What are paper towels used for? Demonstrate how a paper towel gets wet when it is used to wipe up water.

Do you think that we can put the paper towel in water without it getting wet? If so, how? Write down your hypothesis (prediction) and then follow the steps below.

Step 1 – Begin by filling a large container full of water. There must be enough water in the container for you to completely submerge the glass.

Step 2 – Next tear off a section of paper towel and put it into the bottom of the cup. Make sure that the paper towel is big enough to fill the inside of the cup and that it is completely pushed down inside the cup. No part of the paper towel should be above the rim of the cup.

Step 3 – Turn the cup upside down. When you do this, the paper towel should stay at the bottom of the cup. If it slips down, push it back up inside the cup.

Step 4 – Carefully lower the cup straight down into the water. Ensure that the cup does not tip to the side. Lower the cup until it is completely submerged.

Step 5 – Pull the cup straight out of the water. It is important that the cup does not tip to the side when removing it from the water. Remove the paper towel from the cup and make some observations.

What happened to the paper towel? Is it dry?

Is this different than what you expected?

How Does the Dry Paper Towel Science Experiment Work

Even though you can’t see it, air is made up of matter. Because air is made of matter it has mass and volume. Because air has volume it takes up space. This experiment shows the air’s volume!

When the glass is lowered in the water, air is trapped inside of the glass because of the water pushing up from below. Air is less dense than water so it is able to stay on top of the water. The paper towel will not get wet as long as the air stays in the glass. If you tip the glass (even slightly), the air trapped in the glass will rush out in the form of bubbles. Water will then rush in and the paper towel will get wet.

Even More Science Fun

Try the experiment again, but this time slightly tilt the glass to the side as you lower it into the water. What happens? Do you see a bubble rise to the top of the water? What do you think happened? And is the paper towel still dry or did it get wet?