Investigate how to blow huge bubbles on the table.
Early Learning Goal links
- Mathematics ELG: Numerical Patterns
- Understanding the World ELG: Past and Present
- Understanding the World ELG: People, Culture and Communities
- Understanding the World ELG: The Natural World
- Expressive Arts and Design ELG: Creating with Materials
STEM vocabulary to introduce
Liquid, mixture, solution, warm, dissolve, gas, air, blow, big, huge, large, enormous, round, sphere, hemi-sphere, burst, surface, inside, double, triple
Before you start
Show the children the fluid scientist poster and tell the children that they are going to be fluid scientists for this activity.
Ask the children if they know what a fluid scientist does. Fluid scientists are interested in what liquids, and gases are like and how they move and behave. Liquids and gases are examples of fluids
Tell the children about the attributes. Fluid scientists are:
Curious – about what different fluids can do and how they might help us.
Observant – they watch fluids carefully to see how they behave.
Resilient – they try lots of tests before they find the best uses for different fluids.
Tell the children that today they are going curious about how they can blow bubbles on a table. They are going to observe what the table bubbles look like and how many they can blow. They are going to be resilient because it is quite tricky to blow bubbles, but they need to keep trying until they can do it.
What to do – making the bubble solution
This activity works really well with a group of 4 to 6 children sitting around a table with an adult.
Give the children a beaker each. They need 40 ml of warm water. You could get the children to measure this out on a marked measuring container or syringe, or get them to put 4 tablespoons of water into their cups. Alternatively, you can measure out the water for the children.
Ask the children to put half a teaspoon of sugar into their cup. It works well to have one spoon for the sugar, which stays dry, and one each for the children to stir their solution with.
Ask the children to stir their solution.
What has happened to the sugar?
Add a teaspoon of washing up liquid to each cup. This works well if an adult holds the spoon for the children to squirt the liquid into. Ask the children to gently stir their solution.
What colour is the solution now?
What to do – blowing the bubbles
Ask the children to dip their hands into the bubbles solution and then spread the solution onto the table in front of them. You need to cover around 30 cm x 30 cm with bubble solution.
Ask the children to dip one end of their straw into the cup of bubble solution, and put the other end into their mouths.
Show the children how to position their straws at around a 45 degree angle so that the bottom of the straw is touching the table.
Demonstrate how to blow through the straw very gently so that a bubble is created.
The children need to dip the end of their straw into the bubble solution each time they want to blow a bubble.
Remind the children that fluid scientists are resilient, and if they don’t get a bubble the first time, they need to keep trying.
Remind the children that they always need to blow not suck! They may also need reminding to keep the same end of the straw in their mouths and to always dip the other end in the solution. This bubble solution isn’t tasty!
If a child does get bubble solution in their mouth, they should rinse their mouth out with clean water and then spit the water out. Make sure that they don’t swallow the water.
You could ask
- How big is your bubble?
- Can you blow a bigger bubble?
- What shape is your bubble?
- What colour is your bubble?
- What is inside your bubble?
- What is on the outside?
- Why isn’t it floating away like bubbles usually do?
- How is it stuck to the table?
Other things to try – a bubble inside a bubble
Make sure your table is covered in bubble solution and blow your first bubble.
Dip the straw back into the bubble solution in your cup and carefully insert it into your bubble.
Blow a second bubble inside the first bubble, following the instructions as before.
How many bubbles can you fit inside your big bubble?
Can you blow a bubble inside a bubble inside a bubble?
Remember to refer to the children as fluid scientists and praise them for using the attributes. You could say things like:
“You have been resilient like a fluid scientist because you kept trying until you could blow a bubble…”
The science of bubbles
We have put together some useful information about the science of bubbles to accompany this activity. Don’t worry, this is for your information only and to help you answer any questions children may have. We don’t expect you to explain this to the children in your setting!
How do you make bubbles?
Mixing washing-up liquid with water forms a solution. When you blow a bubble, air is trapped by a thin film of your bubble mixture. This film is made of a layer of water sandwiched between two layers of soap.
Why did we use sugar and warm water?
Mixing washing-up liquid with water forms a solution. Adding sugar to the solution helps the bubbles last longer. The water in bubbles evaporates quickly, which makes them pop quickly. Adding sugar slows evaporation, which makes bubbles last longer. We use warm water so that the sugar dissolves in the solution.
Why do the bubbles stick to the table?
Why are the bubbles hemisphere shaped?
Why do bubbles burst?
A bubble pops if the soapy outer skin is broken. This can happen as the water in the bubble evaporates, or if the bubble touches something dry or oily. It can also happen when the bubble becomes too big and there isn’t any more soap to create the sandwich layer. If your bubbles last a really long time, you might see the colours shift as the water drains around the sides of the bubble back onto the flat surface. Eventually, the bubble gets so thin you can barely see it – right before it pops by drying out!
How can I make bigger bubbles?
By blowing gently into the bubble solution you can stretch the bubble solution slowly, forcing more air into the bubble before the pressure causes it to pop.
How can I put my straw into my bubble without it bursting?
Wetting the straw by dipping it in the bubble solution allows it to slide it into the bubble without popping. You can challenge the children to do the same with their fingers:
Can you poke your finger into your bubble without bursting it?
Why do bubbles join together on the table?
A bubble forms the smallest possible shape for the volume of air it contains. To minimise their surface area, bubbles will join together to share one common wall. Three bubbles will meet at the centre, at an angle of 120 degrees, and bubbles that are all the same size will form hexagons. This is also the shape bees create with their wax inside hives.
What you’ll need
- A clean table
- 40 ml warm water per child
- 1/2 teaspoon sugar per child
- 1 teaspoon washing up liquid per child
- 1 straw per child
- 1 teaspoon per child plus one for the sugar
- Beakers or cups
- Measuring cylinders, syringes or tablespoons
- The fluid scientist poster
- 5 minutes to make the mixture
- 10 minutes to complete the activity