Skittle science! Follow FizzicsEd 150 Science Experiments: Comments 13 You will need: Three different coloured Skittles One sugar cube, or a teaspoon of sugar Clear water One flat, shallow white plate A mess bucket and cleaning materials Written by Fizzics Education. Reviewed by Ben Newsome CF. Cite this experiment Copyright Notice Instruction 1 Fill the shallow plate with water to around 0.5cm deep. 2 Arrange the Skittles in a triangle near the centre of the plate. 3 Allow the colours of the Skittles to spread through the water. The colours should form a cross in the middle of the plate. 4 Once a coloured cross is formed, place the sugar directly in the middle of the cross. You should see the colours start to move away from the sugar cube. Read below to find out why! 5 Go further – buy 4 x student activity sheets as extension worksheets. This student science booklet has been created by experienced science educators from the Fizzics Education team. Use these student worksheets as blackline masters for your science class! See all student sheets here 6 Get the Unit of Work on Mixtures here! How can we separate mixtures? What are the different techniques? From chromatography to magnetism, join us to explore the variety of ways we can separate mixtures! Includes cross-curricular teaching ideas, student quizzes, a sample marking rubric, scope & sequences & more 7 School science visits since 2004! – Curriculum-linked & award-winning incursions. – Over 40 primary & high school programs to choose from. – Designed by experienced educators. – Over 2 million students reached. – Face to face incursions & online programs available. – Early learning centre visits too! 8 Online courses for teachers & parents – Help students learn how science really works Why Does This Happen? The Science of Skittle Science! This experiment explores a fundamental concept in chemistry: diffusion. In nature, chemicals naturally move from areas of high concentration to areas of low concentration. This is known as moving along a concentration gradient. You can see this when perfume vapours waft across a room or when cordial spreads through a glass of water. When you add water to the Skittles, the sugar and food colouring in the shells begin to dissolve. Initially, the colours move outwards because the concentration of sugar is highest at the Skittle and lowest in the surrounding water. Interestingly, the colours often meet in the middle without mixing immediately. This is because each Skittle creates a solution with a similar density and sugar concentration; since they are “equal,” they push against each other rather than mixing. If you add a sugar cube to the centre, you create a new area of high concentration. As the cube dissolves, it pushes outwards towards the edges of the plate where the sugar concentration is lower (the solvent is purer there). This outward flow of sugar molecules actually pushes the existing coloured water back towards the edges! Classroom Activity Sheets Create, reflect, and extend your learning with our student worksheets! The Rainbow Effect Try placing a ring of Skittles around the edge of a plate and adding hot water to the centre to watch a beautiful rainbow emerge! Variables to test Find out more on variables here. Solute Competition What happens if the water already has dissolved sugar in it? Does this slow down the rate of diffusion from the Skittles because the concentration gradient is less steep? Candy Coating Try M&Ms or other hard-shelled lollies. Does the presence of chocolate or different types of glazing wax affect how quickly the dye dissolves? Thermal Energy Compare hot water versus cold water. Heat increases the kinetic energy of the water molecules—does this make the rainbow form faster? Solvent Type Would the experiment work with vinegar or milk? Milk contains fats and proteins that might interfere with the movement of the dyes. Always remember to change only one variable at a time to keep your experiment a fair test! âś… Reviewed: April 6, 2026 APA 7 Citation: Fizzics Education. (2018). Skittle science. https://www.fizzicseducation.com.au/150-science-experiments/kitchen-chemistry-experiments/skittle-science/ Copy APA Citation Reviewer This resource was last reviewed for scientific accuracy on April 6, 2026. Ben Newsome CF is the recipient of the 2023 UTS Chancellor’s Award for Excellence and a Churchill Fellow. He is a global leader in science communication and the founder of Fizzics Education. Learn more! From colour changes to slimy science, we’ve got your kitchen chemistry covered! Get in touch with FizzicsEd to find out how we can work with your class. Chemistry Show Years 3 to 6 Maximum 60 students Science Show (NSW & VIC) 60 minutes Online Class Available Read More Enquire Now Magic Crystal Tree Science Kit $4.95 excl. GST View Details Add to Cart Trustpilot STEM Full Day Accelerator - Primary Designed from real classroom experiences, this modular day helps you create consistently effective science learning that directly address the new curriculum with easily accessible and cost-effective materials. Read More Enquire Now Be Amazing! How to teach science, the way primary kids love. $29.95 excl. GST View Details Add to Cart Trustpilot
Allow the colours of the Skittles to spread through the water. The colours should form a cross in the middle of the plate.
Once a coloured cross is formed, place the sugar directly in the middle of the cross. You should see the colours start to move away from the sugar cube. Read below to find out why!
Go further – buy 4 x student activity sheets as extension worksheets. This student science booklet has been created by experienced science educators from the Fizzics Education team. Use these student worksheets as blackline masters for your science class! See all student sheets here
Get the Unit of Work on Mixtures here! How can we separate mixtures? What are the different techniques? From chromatography to magnetism, join us to explore the variety of ways we can separate mixtures! Includes cross-curricular teaching ideas, student quizzes, a sample marking rubric, scope & sequences & more
School science visits since 2004! – Curriculum-linked & award-winning incursions. – Over 40 primary & high school programs to choose from. – Designed by experienced educators. – Over 2 million students reached. – Face to face incursions & online programs available. – Early learning centre visits too!
From colour changes to slimy science, we’ve got your kitchen chemistry covered! Get in touch with FizzicsEd to find out how we can work with your class.
Chemistry Show Years 3 to 6 Maximum 60 students Science Show (NSW & VIC) 60 minutes Online Class Available Read More Enquire Now
STEM Full Day Accelerator - Primary Designed from real classroom experiences, this modular day helps you create consistently effective science learning that directly address the new curriculum with easily accessible and cost-effective materials. Read More Enquire Now
Designed from real classroom experiences, this modular day helps you create consistently effective science learning that directly address the new curriculum with easily accessible and cost-effective materials.
Be Amazing! How to teach science, the way primary kids love. $29.95 excl. GST View Details Add to Cart Trustpilot
Hi Desiree! This experiment is all about concentration gradients. This is the idea that liquids and gases will move from high concentration towards low concentration. In this case, the skittles dissolved and the sugar and the food colour from the skittles went into the water. Once we added pure sugar in the middle of the plate, the dissolving sugar pushed outwards into the low sugar concentration at the edge of the plate… in doing so pushing the food colours from the sugar outwards. Concentration gradients are important in chemistry to understand how chemicals behave in reactions. When we did this with hot water the same effect occurred, however, it was much faster, which shows that reactions occur much more quickly when there is more heat energy available. Hope you have fun with the activity! Reply
I think there is something else happening here in this experiment that is needed to explain why the colours don’t mix and it is to do with dissolving. If you look carefully at the coloured mixtures being pushed from the sweets, it appears as though they are fine particles of colour sitting on the bottom. I.e. they have not dissolved. They are a fine suspension perhaps of coloured particles. Because they are is suspension they do move from high to low concentration but when they meet I wonder if they meet a physical barrier which impedes their movement i.e. a load of suspended particles. Reply
Thanks for your comment! In essence, this experiment shows that chemicals tend to move from where there is more to where there is less (also known as a concentration gradient). Glad you enjoyed the experiment! Reply
Hi Paige! This one is a physical change as it is about dissolving a solid into a liquid. In order for a chemical change to have occurred, you need to have a new molecule formed that wasn’t there before. Reply
Hi Kacey! At first, the skittles outer covering dissolves. This brings sugar and food colouring molecules towards the centre of the plate. When you add the extra sugar in the centre of the plate, you will have noticed that water in the plate rushes into the additional sugar as it dissolves. Reply
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