Rainbow Water Wheel
You will need:
6 glasses or clear plastic cups
red, yellow and blue food colouring
a little patience and time…
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.
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?
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…
Now that you have mixed colours with pigment, try mixing the colours of light with this flashlight and shadow activity from Fizzics Education.
Let Professor Astro Cat introduce you to light and colour with Flying Eye Books and National Geographic Kids.
Explore the science of light and colour in depth with Pokapū Akoranga Pūtaiao, the Science Learning Hub of New Zealand.
Try 7 Ways to use Food Colouring in Play with Powerful Mothering
Early Years Questacon Science Time: Colour and Light
Little scientists can explore colour, light and rainbows with Questacon, The National Science and Technology Centre.
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
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