Make Mad Scientist's Slime

Sometimes gross things are just right like this slime-making science activity, which is perfect for Halloween!

By Liz Heinecke
Oct 27, 2017



Oct 27, 2017

Editor's note: This post was originally published on October 28, 2016. 

Kids and slime. Slime and kids. There's just something about them that goes together.

Which is why this experiment is perfect for them. It's fun and kicks creativity into high gear as your young scientists measure, stir, and play with color. And in terms of prep, it's perfect for you, using just three household items and water.

Because laundry detergent is used for this experiment, young children should be supervised.

What You'll Need

  • School glue
  • Laundry detergent containing sodium borate, like Borax
  • Green food coloring
  • Water

How to Make the Slime

Step 1: Have your junior scientists measure and mix together equal parts glue and water in a bowl. For example, 1/4 cup glue combined with 1/4 cup water. Stir.     

Step 2: Let your children choose a color, add a few drops of food coloring, and stir again. Glue is a chemical called a polymer, and this is your polymer solution.

Step 3: To make the detergent solution, have them add a cup of warm water to a jar or bowl. Add a heaping tablespoon of Borax to the water. Shake or stir. Don’t worry if the powder doesn’t all dissolve. This is your cross linking solution.

Step 4: Ask your children what they think will happen if they add the detergent to the glue.

Step 5: Let your children add a teaspoon at a time of the Borax solution to the glue/water/food coloring mix. Following each addition, stir the mixture. Long strings will begin to form and stick together like goo. Keep adding Borax until the mixture doesn’t feel sticky and forms a shiny rubber-like substance. 
Note: If you add too much Borax solution, it will feel wet, but you should be able to squish it around with your hands to absorb the extra solution! 

Step 6: Remove the slime from the bowl. Have your children roll it into long snakes or form it into bouncy balls. Store the slime in a plastic bag.  

Step 7: Let your children try their hand at chemical engineering by making up their own slime recipe. Tell them that if they add less water to the glue before adding detergent, they can make rubber balls. If they want slimier slime, have them add more water to the glue before adding the Borax. (But make sure to add any water and food coloring to the glue before adding the Borax!)

The Science Behind the Fun

Polymer means "many parts." Glue is a polymer, which is a long chain of molecules linked together. You can think of it like a chemical chain

Sodium borate (Borax) mixed with water makes a cross-linking substance, which makes the glue polymer chains stick to each other.  As more and more chains of the glue (or polymer) solution and the Borax (or cross-linking) solution stick together, they can’t move around and the mixture gets thicker and thicker.  Eventually, all the chains are all bound together and you have slime!


You can find more experiments like this one at, and in my books Kitchen Science Lab for Kids (Quarry Books) and Outdoor Science Lab for Kids (Quarry Books).

© Quarry Books, 2016/Kitchen Science Lab for Kids
Featured Photos Credit: © Quarry Books

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