It’s a well known fact—kids LOVE getting messy! Making slime is a great way for kids to learn about the science of polymers while reaping the benefits of sensory play. Slime is a polymer. Polymers are made up of long, bendy molecules that are kind of like spaghetti. There are lots of good examples of polymers, like plastic cups, balloons, and even skin.
Polymers actually have two parts. The long, bendy polymer molecules are not very sticky, so to make a big polymer, we need to add a "cross-linker." We will be talking more about how a cross-linker functions in regard to making a borax solution. Read through the rest of the instructions to get a mini science lesson on the sticky substance kids can't seem to get enough of.
If you are making slime as a STEAM activity, discuss what a solution is with your child. A solution is when you mix together two or more ingredients, that once combined cannot be separated. A great example of a solution is hot chocolate: when you mix together the milk and cocoa, the cocoa cannot be taken out of the milk. Making a slime solution requires very few materials for a whole lot of fun.
Equipment / Tools
- Measuring spoons
- Measuring cup
- Mixing bowl
- 1 cup warm water
- 1 teaspoon borax
- 1 cup glue (clear or white)
- Wooden ice pop stick
- Food coloring (optional)
Pour Glue into Mixing Bowl
Pour about a cup of clear or white glue into a mixing bowl.
If you want your slime to have more of a “flubber” feel, try adding a tablespoon of water to your glue.
Measure Warm Water for the Borax Solution
Measure out 1 cup of warm water into a jar. small bowl, or large liquid measuring cup. You'll use this in the next step.
The best way to dissolve borax is to use warm water to help the borax dissolve into the solution.
Add Borax to the Warm Water
- Measure out 1 teaspoon of borax. The borax (sodium tetraborate aqueous) is going to act as a cross-linker.
- Add the borax to the warm water.
- Set your solution to the side for now.
Cross-linkers are like fork molecules; they hook our long spaghetti polymer molecules together to make our larger polymer—slime!
Add Sparkle or Color to the Glue
With your water and borax solution set to the side, focus your attention back on your glue. Now's the time to decide what you want your slime to look like.
- For sparkle, add in as much or as little glitter as you'd like.
- For color, add in a few drops of food coloring.
Mix Together the Glitter and Glue
- Use a wooden ice pop stick to mix together your glitter, glue, and food coloring.
- Stir until everything is combined well.
Add Borax Solution to the Glue While Mixing
- Bring your cup of water and borax solution closer to your mixing bowl and measure out 1 tablespoon.
- Pour the tablespoon of the water and borax solution into your mixing bowl of glue and stir fast.
- You'll see a fast chemical reaction because two things were mixed together to create something new.
If your new polymer (slime) is too sticky, add a teaspoon of your solution and keep mixing.
Knead the Slime
- Scoop out the slime from the bowl.
- Roll up your sleeves and dive in with two hands. Kneading is necessary so your slime is less sticky. The kneading action makes sure the borax solution is fully integrated into the glue.
- Keep kneading until the slime is at a consistency that your kids find fun to play with.
If you don't want your entire home to become covered in slime, limit the areas where your kids can use it. We suggest playing with slime on a tray at a table and definitely not on top of your favorite oriental carpet.