Discover a new way to make bubbles

Basic concepts

Chemistry	Gases	Molecules

The following is an introduction:

Outdoor soap making is a classic and fun pastime for all ages. But do you know how pumps actually form? In this experiment, you will learn how bubbles form and how to create them with the gases of your breath.

Background

Pumps are bags of soap and water that are filled with air, like your breath, which contains nitrogen, oxygen and carbon dioxide. When you mix water and soap and then blow air into the mixture, the soap forms a thin wall and traps the air, creating a bubble! The soap film is made up of three layers: a layer of water molecules between two layers of soap molecules. Millions of these molecules will come together to give the bubble a spherical shape.

Soap pumps aren't the only bubbles you can find. In fact, you can find bubbles in many liquids, such as carbonated drinks (think soda). Even in running water you might be able to see little bubbles. It's important to note that these bubbles will always be in the water or floating on the surface of the water, unlike soap bubbles that can float freely in the air. Can you think of any other types of bubbles?

Materials

• Adult helper
• 1 small plastic bottle
• 1 towel (or sock)
• 1 rubber band
• 3-4 drops of food colouring (of different colours)
• 1⁄2 cup of water
• 1⁄4 cup dishwasher
• 1 small bowl
• 1 cutter or scissors

Preparation

Ask an adult to cut the bottom of a plastic bottle with a cutter or scissors.

The procedure

1. Use a rubber band to hold the towel to the open side of the bottle.
2. Add the water and dishwasher in the small bowl. Remove with a spoon.
3. Add food coloring directly to the towel. Let your creativity fly, try to make a fun pattern!
4. Dip the towel in the soap solution.
5. Blow hard through the mouth of the plastic bottle.
6. Look what happens. You just made a bubble snake!

Observation and results

• Why do we add dishwashers to the water solution?
• What gas is trapped inside the bubbles?
• What happens if you double the amount of dishwashers in the water solution?
• What happens if you use a 2-liter soda bottle? Will the bubbles be bigger?
• What happens if you use a thick towel instead of a thin towel?

The towel plays an important role in this experiment, because the fibers in the towel absorb the dishwasher until we use our breath to push out the exhaled gas and form bubbles.

You can see that some towels work better than others; the best ones are thick enough to absorb the bubble solution, but thin enough to push air easily through the fibers.

And why do we add food coloring to the towel instead of the water solution? Our ideal goal is to create a chain of multicolored bubbles. If we add the food dye to the towel, we can keep sections of orange, red, green, blue, purple or whatever colors you choose! This is perfect for creating a rainbow bubble snake. However, if we had added all those colors to the water solution, we would have returned the water black. That solution would give us a chain of black bubbles instead of a colorful bubble snake!

Keep experimenting with different color variations, different towel thicknesses and draw your own conclusions.

Pick it up!

When you're done, remember to clean everything up by discarding or recycling materials.

Adult supervision and safety first

• Follow the experiment instructions carefully.
• A responsible adult should help with each experiment.
• While home science experiments are very interesting ways to learn about science in a hands-on way, keep in mind that some may require participants to take extra safety precautions and/or not leave everything to chance.
• Adults should handle or help with sharp or potentially harmful materials or objects.
• Adults should review each experiment and determine the appropriate age for student participation in each activity before conducting any experiment.