Bubble Trouble

In this activity your students will work as a team to make the best bubbles.

Year groups: reception – year 2 (ages 3–7)

Educational objective

By trying out and testing different apparatus students will be able to investigate what makes the best bubbles and adapt their approach to try and improve their bubbles. This activity is ideal for introducing simple investigation skills to younger children.

Key student learning

Investigative skills – pupils will make predictions and test them, make changes based on their results and test them again.
Observation and evidence are important in reaching conclusions in science.
Describing and exploring the properties of water.
Describing and exploring the changes in the properties of water in bubble mix.

Materials, per group

500 ml of bubble mixture, made to the Science Museum recipe
Spoons
Hand whisk

You can either give your students pre-made bubble-blowers or get them to make their own using the 'Making Bubble Blowers' activity sheet above using the following materials:

Bowls and plates made of expanded polystyrene or other plastic
Coat hangers
Paperclips
String
Scissors

Teachers’ materials

Metre ruler or tape measure
Camera (optional)
Classroom assistants or parent helpers (this activity is quite messy, so the more people you have to help the better)

Science Museum Bubble Recipe

1/2 mug of washing-up liquid
Warm water(enough to fill 3/4 of a bucket or tub)
I mug glycerol (available from chemists)

Bubble mix is dependent on the environment and temperature so you will have to experiment to find the best mix.

Put the water in the bucket, add the glycerol and stir slowly while gradually adding the washing up liquid.

How to run the bubbles investigation

Before you start:

Ensure that all tables are protected with a covering such as plastic washable tablecloths, newspaper or dustbin liners that have been cut open.
Have all the equipment in place on the tables.
Make up your bubble mixture, and leave it to stand in a warm place for a couple of hours if possible. Bubble mix is a bit like a fine wine – the longer you leave it to settle, the better it becomes. Just don’t try drinking it!

With your pupils:

Set the challenge to make the best bubble. You can run the activity for anything between 15 minutes and an hour depending on how much depth you go into. We recommend about 45 minutes.
Get each group to try out different ways of producing bubbles by making their own bubble-blowers. Allow students free investigation with the equipment provided, referring to the images in the 'Making Bubble Blowers' activity sheet for inspiration if necessary. For a shorter investigation, provide a selection of ready-made materials, e.g. a coat hanger wrapped in string.
Ask each group to define what would be the ‘best’ bubble and ask them to investigate how they will make it. For example, if making foam it might be the tallest tower; if blowing bubbles it might be the largest bubbles or the ones that last longest. Get pupils to try out the different bubble-blowers that they have made and record what implement and technique they used to make what they have defined as the ‘best’ bubble.
Discuss as a class what characteristics make the best bubble – is it the largest, the longest lasting, the tallest foam…? Use this discussion to introduce the idea that people have different views on what is ‘best’. Encourage groups to demonstrate their ideas.
Allow more time for investigation and modification after the group discussion, encouraging pupils to keep a record of what they are using and what they have found out. Recording can be in the form of photographs, pictures or measurements. Additional adult help would be useful here!
Allow time for each group of children to demonstrate what they have come up with and present their scientific findings about what makes the best bubble.

Practicalities

This investigation is messy, so have cleaning materials available including absorbent cloths, towels and aprons. Allow time in your planning for washing hands at the end.
Using glycerine in your bubble mix will help the bubbles to last longer and be stronger, potentially allowing more investigation. Don’t add too much, though, as the bubbles will become too heavy.
Bubble mix is very dependent on outside forces (temperature, humidity, etc.), so you should always mix and test your bubble mix in advance to ensure that it works, even if you have followed a recipe.
Although it is always tempting to run messy bubble activities outside, remember that bubbles don’t like air that is too dry, or too much wind. On hot days mist the air with a plant water mister to help the bubbles last longer. In winter try placing a couple of bowls of water near radiators for an hour before you start the activity. And don’t even attempt to blow bubbles in an air-conditioned room.

Discussion

This activity provides great scope to discuss complex concepts such as predicting and testing, in a very visual, fun way. It is also useful for introducing the idea that not everyone agrees on what is ‘best’ or ‘better’ and that different views can be equally valid.

What is the best bubble?
Does everyone agree on what the best bubble is? If not, why not?
Which blower makes the best bubble?
Which mixture makes this bubble the best?
Can you make bubbles from just water?
Do you think you could make the bubbles even better? How?
Did you change anything that you were doing along the way? Why?
Do you think there are other ingredients that you would want to try?
What else could you use to blow a bubble?

Extensions

Rather than running an entirely open-ended investigation, you can introduce competition, by defining what the challenge is for everyone – for example, to make the largest bubble, the bubble that lasts the longest or the strongest bubble (i.e. bubble foam that can hold a polystyrene bowl with five marbles in it). Groups compete against each other to complete the challenge. This also works well as a parent/carer activity at home or in the classroom.
Look at the shapes that bubbles make and learn about other 3D shapes and whether it is possible to get a bubble to make that shape. For example, does a square bubble-blower make a cube-shaped bubble?
Blow paint bubbles onto paper by adding paint to your bubble mix and using a straw to blow them. This is a good way to record how large the bubbles were.
Use the bubble activity to look at other things that float in the air and the similarities and differences between them (e.g. seeds or balloons).
Together with your students shine a light under the bubbles so that you can look at the rainbow colours and talk about why this happens.
By doing the Milk Magic demonstration that appears in the Kitchen Science resource you can see the effect that washing-up liquid has on milk.
You could follow up this investigation by getting the class to agree on the best bubble mix and blower and making them together in the next lesson.
You could give your students three different types of pre-made bubble mix so that they can work out which mixture makes the best bubbles.
You could do a further activity allowing students to modify the bubble mix itself to produce the best mixture for their chosen method of producing bubbles. This introduces the idea of ‘the right tool for the right job’.
You could book the Science Museum’s Outreach Team to bring The Bubble Show to you, or arrange to see it on a visit to the Museum!

Links to everyday life

We can see and experiment with bubbles in everyday life. When you are doing the washing up you can often see lots of bubbles. They are made by mixing the water that you are washing up with and the washing-up liquid. You may be able to see a difference in the bubbles depending on what washing-up liquid you use and the temperature of the water. Can you blow your own bubbles using your own hands?

Bath time is also a great time to explore bubbles. These bubbles are made from the bubble bath, shampoo or shower gel that you are using. You can try making bubbles with you hands or even use your arms to make bigger bubbles. Which do you think works best?

Bubbles also have a very practical use in your toolbox. A spirit level is a glass tube filled with ethanol and a single bubble. It indicates that a surface is level when the bubble is positioned exactly between two lines on the tube. You can see a modern spirit level in the Making the Modern World gallery in the Science Museum.

Curriculum links

Key Stage 1:

Ideas and evidence in science
Investigative skills – planning, obtaining and presenting evidence and considering evidence and evaluating
Changing materials
How the shapes of objects made from some materials can be changed
Describing changes that occur when materials are mixed

Foundation Stage:

Students will identify and find out about some features of living things, objects and events they observe during this activity
Look closely at similarities, differences, patterns and change
Build and construct with a wide range of objects, selecting appropriate resources, and adapting their work where necessary
Select the tools and techniques they need to shape, assemble and join the materials they are using
Activities based on first-hand experiences that encourage exploration, observation, problem-solving, prediction, critical thinking, decision-making and discussion
Model investigative behaviour and raise questions such as, ‘What do you think?’, ‘Tell me more about...?’, ’What will happen if...?’, ‘What else could we try?’, ‘What could it be used for?’ and ‘How might it work?

The science – an introduction

A water molecule is made up of hydrogen and oxygen atoms that are attracted to each other. This attraction also causes surface tension, an attractive force that occurs on the surface of liquids. This means that if you try and blow a bubble using just water it will not work. When soap molecules (washing-up liquid) are added to water this reduces the surface tension and enables you to blow bubbles.

Bubbles will always form a sphere because this shape has the smallest surface area for the volume of air in the bubble, and so takes the least energy to form.

Web Links

If you are interested in finding out more about bubbles check out The Exploratorium, About.com and Chemical and Engineering News.

Links to the Museum

Outreach Shows

The Bubble Show