Slime is fun to make — but it also makes a great science fair project. Instead of just mixing ingredients, students can test how slime changes when one variable is adjusted. By measuring stretch, texture, and reaction time, kids learn real chemistry and physics concepts while working with a familiar material.
What Makes Slime Scientific?
Slime forms from a chemical reaction between glue and an activator.
The glue contains long chains of molecules called polymers.
When borate ions from the activator are added, the chains connect in a process called cross-linking.
This creates a non-Newtonian fluid — a substance that behaves like both a liquid and a solid.
Because the material changes with the conditions, slime is perfect for experimentation.
👉 Read the full explanation: Basic Slime Science
💡 This guide shows how to turn basic slime into a structured experiment using the scientific method.
Science Concepts Students Can Test
A slime project explores real scientific ideas:
• polymers
• chemical reactions
• states of matter
• viscosity
• elasticity
• variables and controlled experiments
Materials Needed
- white or clear school glue (PVA)
- slime activator (saline solution, liquid starch, or borax solution)
- baking soda (if using saline solution)
- water
- mixing bowl
- measuring spoons
- food coloring (optional)
- ruler or tape measure
- timer
- notebook for recording data
👉 See ingredient details: Slime Ingredients Guide
Basic Slime Setup (Control Batch)
Students first create a standard slime to use as the control.
- Mix ½ cup of glue with ½ cup of water
- Add food coloring if desired
- Stir in baking soda (½ teaspoon)
- Add 1 tablespoon of saline solution slowly
- Knead until stretchy and no longer sticky
This batch becomes the baseline for comparison.
👉 Full recipe instructions: Homemade Slime Recipe
Choosing a Testable Question
Every science fair project starts with a question.
Good slime questions change only one variable:
- Does more activator make the slime less stretchy?
- Does temperature affect slime firmness?
- Do glue brands behave differently?
- Does water change viscosity?
Slime Investigation Ideas
These slime activities turn play into real experiments. Instead of just making slime, kids test variables and observe how materials behave under different conditions.
Physical Property Slime Experiments (Material Behavior)
These investigations explore how slime’s structure changes in response to changes in forces, temperature, or ingredients. The slime itself stays the same substance — only its properties change.
Glue Brand Comparison
Use different brands of glue to make separate batches of slime.
Learn how scientists describe differences in materials: observable properties of matter
Measure:
- elasticity
- smoothness
- strength
Discuss: Do all glues form the same polymer network?
Temperature Test
Chill or refrigerate one slime and leave another at room temperature (do not heat).
Measure:
- stretch distance
- firmness
- reaction time when pulled
Discuss: How does temperature affect movement of molecules?
Add-In Experiment
Start with a basic slime, then add different materials to separate samples.
Try:
- foam beads → Foam Bead Slime Recipe
- sand → Sand Slime Recipe
- clay → Butter Slime Recipe
Measure:
- structure
- thickness
- ability to hold shape
Discuss: How do added particles interrupt the slime network?
Connect this to real science vocabulary: physical properties of materials
Magnetic Slime Investigation
Add iron oxide powder to the slime and test the magnetic attraction strength.
Observe:
- movement speed toward magnet
- shape changes
- stretching behavior
- Discuss: How can a force act on a material without touching it?
- Learn more about invisible pushes and pulls: forces and magnetism
👉 Try it here: Magnetic Slime Experiment
Slime Bubble Investigation
Inflate slime using lifting and straw methods to test how polymers trap air and stretch without breaking.
Observe:
bubble diameter
stretch distance before popping
film thickness
time bubble holds air
Discuss: Why can slime hold air like a balloon but still flow like a liquid?
Learn more about material behavior: observable properties of matter
👉 Try it here: Slime Bubble Activity
Chemical Reaction Slime Experiments (Matter Changes)
Unlike the tests above, these experiments create a new substance — a gas — instead of just changing the slime’s texture.
Fizzing Slime Volcano
Combine slime with a baking soda and acid reaction to observe bubbling and gas formation.
Observe:
- bubble speed
- reaction height
- reaction duration
- Discuss: What evidence shows that a chemical reaction occurred?
- Compare reactions to simple material changes: chemical vs physical change
👉 Try it here: Fizzing Slime Volcano Experiment
Recording Data
Students should measure instead of guessing.
Possible measurements:
- maximum stretch length (cm)
- time before breaking (seconds)
- drop speed (seconds)
- bounce height (cm)
Recording numbers turns play into real science.
Using the Scientific Method
- Ask a question
- Form a hypothesis
- Change one variable
- Record results
- Compare to the control slime
- Draw a conclusion
👉 Learn about the Scientific Method here. Get help writing a hypothesis, choosing variables, and drawing conclusions
Presenting the Project
A slime science board should include:
- question
- hypothesis
- materials
- procedure
- data table
- graph
- conclusion
👉 See how to set up a Science Fair Board here. Photos of each slime help show differences clearly.
Why Slime Works Well for Science Fairs
Slime is ideal because it:
- changes visibly
- reacts quickly
- is safe to handle
- allows measurable results
- demonstrates real chemistry
Students can easily repeat trials and improve their investigations.
More Slime Help
Printable Slime Science Guide
After testing one variable in an experiment, students often want to compare more variables.
This printable Slime Science Guide includes investigation pages, recording charts, and experiment prompts that help organize results and create a complete science fair presentation.
who is the author of this website?? i need to know for a science project
My name is Sarah McClelland.
Everything looks so pretty! I need some help, I can’t find sta-flo liquid starch in my country, I tried corn starch but its too thick,I tried niagara spray and liquid but won’t work either. I need it to be a flubber starch, with iron to do magnetic starch 😀 Any advice is welcome
What country are you in? Can you find saline solution containing boric acid and sodium borate?
Please email me at sarah@littlebinsforlittlehands.com
whenever i try make slime it never works and the first time i made a home made slime it was way too sticky and to make work we had to mix store bought slime in to make it activate
Well I am happy to help if you want to email me sarah@littlebinsforlittlehands.com