Bubble Painting

You will need:

•Paper
•Containers with wide tops (e.g. plastic cups, yoghurt pots)
•Powder or liquid paint
•Washing-up liquid
•Straws

What to do:

1.Put a squirt of paint and a squirt of washing-up liquid into one of the containers.
2.Add a little water and mix well until the mixture is runny enough to blow bubbles with.
3.Using the straw, blow into the mixture (Okay Mr Bluechops - who sucked instead of blowing?) until the container is so full of bubbles that they rise above the top rim.
4.Quickly take a piece of paper and lightly touch it onto the bubbles. As they touch the paper, the bubbles will burst. You will be left with a lovely pattern of circles. Leave to dry then build up layers of colour.

What’s going on?

Surface tension of water makes it impossible to stretch out to create a thin film or bubble on its own. There is a strong attraction between water molecules, preventing them from being stretched thinly enough to produce a bubble. However by adding soap to water, the soap reduces the surface tension and allows bubbles to form.
A soap film always pulls in as tightly as it can, just like a stretched balloon. A soap film makes the smallest possible surface area for the volume it contains. Most bubbles are spheres because it is the shape that has the smallest surface area compared to its volume.