Rainbow Water Wheel

You will need:

  • paper towel

  • 6 glasses or clear plastic cups

  • red, yellow and blue food colouring

  • scissors

  • water

  • a little patience and time…

How to:

Materials
Step 1. Cut 6 long strips of paper towel.
Step 2. Place your 6 cups in a circle with the edges touching. Half-fill every second cup with water, leaving the others empty. Add red food colouring to one cup of water, yellow to another, and blue to the third.
Step 3. Drape the paper towel strips between the cups, making a circle. Each strip should hang in an empty cup on one side, and touch coloured water on the other side. 
Step 4. Now watch and wait!
Over time, the water will ‘climb’ up the paper…
… crossing into the empty cups …
… to mix new colours!
Did it work? Which colours do you have now?

Reflect and Extend

  • Which colours appeared in the ‘empty’ cups?

  • How long did it take for the ‘empty’ cups to be half as full as the first three? Repeat the experiment with a timer to find out.

  • What happens if you leave them overnight? Or longer?

  • Did any of the colours move up the paper faster than others?

  • Dip a piece of paper towel into the new colours to sample them.
    Which colours are the strongest and brightest?

  • Repeat the experiment using fabric instead of paper towel.
    Does it work differently? Better? Worse?

Science at work: Capillary Action

Because of gravity, liquid usually flows downwards rather than upwards. So how is the coloured water climbing up the paper towel?

Capillary action is a process during which a liquid, like water, moves up something solid, such as a tube or porous material. Porous means something with a lot of small holes.

Capillary action is very important in nature because it’s how plants take in and distribute the moisture they need to grow. The water enters from the roots, and moves upwards to different parts of the plants using tiny tube structures.

CAPILLARY ACTION - KIDDLE

CAPILLARY ACTION - SCIENCE ABC

Trial and Error

Science doesn’t always go according to plan!

STEAM Powered Family tried this experiment and discovered some interesting things along the way. Where did they go wrong, and what can we learn from their experience?

STEAM-POWERED FAMILY: WALKING RAINBOW

Learn more: Light, Pigment and Primary Colours

Primary colours are the basic building blocks of colour. By mixing primary colours together you can make all the other colours! But did you know that the primary colours of pigment are different from the primary colours for light?

The physical substance of colour (whether in plants, paint or printing ink) is called pigment.
The primary colours of pigment are red, yellow and blue. 

Food dye is a kind of edible pigment. In this experiment, we mixed the primary colours to create the secondary colours of pigment: orange, purple and green.

Light is the purest form of colour. All the colour we see in the world is created by light rays bouncing around! The primary colours of light are red, blue and green. 

Take it further…

Early Years Questacon Science Time: Colour and Light

Little scientists can explore colour, light and rainbows with Questacon, The National Science and Technology Centre.

DOWNLOAD QUESTACON ACTIVITY SHEET

Curriculum Connections

EYLF Outcome 4
Children are confident and involved learners  
Children develop a range of skills and processes for learning

General Capabilities: Critical and Creative Thinking
Identify and explore ideas and reflect on processes

Science F-4

  • Strand: Science Inquiry Skills
    E.g. Participate in guided investigations to explore and answer questions ACSIS025, ACSIS038

  • Strand: Science Understanding: Chemical Sciences
    E.g. Everyday materials can be physically changed in a variety of ways ACSSU018

  • Strand: Science Understanding: Biological Sciences
    E.g. Living things grow, change and have offspring similar to themselves ACSSU030

More activities to try

Storytime with Temeka: Harold and the Purple Crayon Temeka reads Harold and Purple Crayon by Crockett Johnson
Try It
Creature Sounds – Superluminal Discover the creatures in Superluminal and explore the sounds they make.
Try It
Pass the Story Build imagination and improvisation in this interactive group story-telling game
Try It