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NESA Accredited Teacher
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High school chemistry & physics specialist 30+ years
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The Crazy Scientist in primary schools — 15 years
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International conference presenter on science education
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Creator of the LAB™ Learning System
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Curriculum aligned: NSW Science & Technology K–6 (2024)
A picture is worth a thousand words — check this out and see if you can spot the science hiding in plain sight.
From the LAB
What you will need
1 teaspoon psyllium husk powder — sold as Metamucil
1 cup cold water
Food colouring — optional; add to the water before mixing; silver or grey makes a convincing snail-slime colour
A microwave-safe bowl — use a LARGE bowl; the mixture will overflow during heating
A microwave
Oven mitts — the bowl will be extremely hot
A spoon for stirring
How to do it
1
Mix the powder
Measure 1 teaspoon of psyllium husk powder into your large microwave-safe bowl.
Add 1 cup of cold water. If you are using food colouring, add it to the water now. Stir well for 30 seconds.
Hold the bowl up and look at what you have — it should look like slightly cloudy water, with just a hint of thickness.
3
Watch it form
Adult help needed
Place the bowl in the microwave. Microwave on high for 2 minutes — watch through the door the whole time. You are looking for the moment the texture changes.
What do you notice starting to happen?
Does it look like it is thickening? Are there bubbles? Record what you see at the 1-minute mark and again at the 2-minute mark.
5
Cool & Investigate
Carefully remove the bowl using oven mitts.
Place it on a heatproof surface and leave it to cool completely — at least 10 minutes. Do not touch until the adult confirms it is safe.
2
Make your prediction
Before anything goes near the microwave, stop and predict. A snail’s slime is stretchy, glistening, and tough enough to let the snail slide across a razor blade.
You are going to microwave this cloudy water for up to 5 minutes.
4
Last blast
Continue microwaving, checking every 30 seconds. Watch for the moment the gel begins to rise. How high does it go? Does it reach the rim?
Does it overflow? Compare what you see to your prediction from
6
Observations
Once completely cool, use a spoon to scoop out a piece and test its properties. Is it stretchy or does it snap?
Does it hold its shape when you set it down?
Does it feel wet? What happens when you press on it quickly versus slowly?
Did it work? Share the science! Tag @the_crazy_scientist on Instagram — we love seeing your experiments!
Snail Slime
Designed by Darin Carr (BSc, DipEd)
NESA Accredited Teacher Chemistry & Physics Specialist
Creator of the LAB™ Learning System
How does a snail cross a razor blade without getting cut? The answer is in its slime — and a single teaspoon of plant powder can show you exactly how it works.
5-12 yrs
Easy
15
min
Stage 1-3
>
Snail Slime
The Crazy Scientist LAB Learning System™
Every experiment follows The Crazy Scientist Lab Learning System™ — a simple way to help kids think like real scientists.
We
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LINK to what they already know,
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ACTIVATE curiosity through hands-on discovery
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BUILD understanding that actually sticks.
Have you ever watched a snail move? It glides on a shimmering trail of slime — but that slime is doing something remarkable. It is liquid enough for the snail to slide on, yet sticky enough to let the snail climb a vertical wall of glass.
Snail slime is not just wet. It is a special kind of material that changes its behaviour depending on pressure. Push on it and it flows. Let it sit still and it grips.
Scientists call this a non-Newtonian fluid. Snails have been using it for 500 million years. Today, you are going to make a material from a plant powder that shares some of those same properties.
Mix it with water and put it in a microwave. Something will happen at around the two-minute mark.
Predict: what do you think will come out — and will it behave anything like snail slime?
Think back to the moment the mixture started to rise in the microwave. At that point, was it a solid, a liquid, or something in between?
The slime that came out is firm and rubbery — but it started as cloudy water. What do you think caused it to change?
The psyllium chains absorbed water and swelled when heated. If the chains absorbed the water, where is the water now — still in the bowl, or trapped inside the slime?
When you pressed on the cooled slime slowly, did it behave differently from when you pressed quickly? Snail slime flows under slow pressure and resists fast pressure. Did your slime do anything similar?
The slime is edible. The ingredients are a plant fibre and water. Does that change how you think about what ‘slime’ is — or does it make you rethink what ‘chemistry’ means?
Snail mucus is used in commercial skin-care products — it is added to face serums and creams because it holds moisture and promotes skin repair. Psyllium also holds moisture. What advantage might a natural, edible, skin-safe hydrogel have over a synthetic one?
The key property of snail mucus is that it is non-Newtonian: it behaves differently under different forces. Cornflour and water is another non-Newtonian fluid — it goes solid when hit hard. How is that different from what snail slime does — and which property would be more useful for a snail climbing a wall?
"Want the full teacher guide? The Crazy Scientist Lab includes classroom delivery tips, how to manage the WOW moment, differentiation for Stage 2 & 3, — ready to teach tomorrow."
Think Like a Scientist
Scientists don't just do ONE experiment; they change one part of the experiment (independent variable) and then see how it affects another part of the experiment
(dependent variable)
Change ONE variable and test again.
Does the amount of psyllium husk change how stiff the result is — does more husk produce a firmer, stiffer slime, or does it make no difference?
Does the microwave time change the texture — does longer microwaving produce a firmer result, or does it make the slime softer and more watery?
🧪 Try it! Change ONE thing and test again. What did you discover?
Want to go deeper? Tap a section below to explore. ▼
The Science Behind It
Snails have been engineering slime for 500 million years — and today you built something that works on the same basic idea.
A snail's mucus is mostly water, but the water does not just sit there — it is held in place by a tangle of very long molecules, a bit like water trapped inside a jumbled ball of wet string. The molecules in real snail mucus are called glycoproteins: chains of protein with sugar units attached.
Psyllium husk has a similar type of molecule called a polysaccharide — a very long chain made entirely of sugar units (that is what the name means: poly = many, saccharide = sugar). Both form gels the same way: the chains soak up water, swell up, and tangle together, trapping the water between them.
When you stirred the powder into cold water, those chains started absorbing water straight away — but slowly. That is why the mixture looked cloudy and not much else. In the microwave, heat gave the water molecules extra energy.
Those excited molecules pushed harder against the swelling chains. Steam and air got trapped inside the thickening gel, and when they had nowhere to go, the whole thing expanded upward — just like lava forcing its way up through a volcano.
Once you removed the heat, the chains cooled and tangled together permanently, locking the water inside. That is why the result is firm and rubbery instead of liquid.
To compare this natural process with a synthetic one, try [The Polymer Factory]. For another edible, heat-set material that sets using protein chains instead of sugar chains, try [The Sweet Lab].
Extension: G&T Years 5 & 6
Vocabulary
Know a parent or teacher who'd love this? Send it on! 👇
The Crazy Scientist books
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Designed by a practising NSW classroom teacher (30+ years experience), these books directly support NSW Science & Technology (2024) outcomes and reinforce “Working Scientifically” skills.
Perfect for classroom libraries or home explorations.
For teachers (YouTube)
— Science Before the Bell
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