How to: Make Slime

Homemade slime is an entertaining teaching tool.

You might not think something as gross as slime can be educational, but homemade slime is an excellent teaching tool. You can use slime to teach kids about Newtonian and non-Newtonian liquids -- liquids that flow, such as water and liquids that sometimes behave as solids, such as quicksand and homemade slime. Once you've mixed up a batch of slime, show kids the difference by comparing the way slime behaves to the way water behaves. For example, smack a bowl of water with a spoon to show kids that water splashes on impact. When you smack the slime with a spoon it stays still because it reacts to force like a solid.

Things You'll Need

• 1 cup cornstarch
• Water
• Food coloring
• Resealable plastic zipper bag

Instructions

1. Pour cornstarch into the resealable plastic zipper bag.

2. Pour water into the bag with the cornstarch 1 teaspoon at a time. The amount of water you use can quickly change the slime into a liquid, so be sure to add water a little at a time. Stop adding water once the mixture looks slimy and not runny. If you add too much water, add a little more cornstarch.

3. Add food coloring to the bag if you want colored slime. Add food coloring a few drops at a time. Add more food coloring for more vibrant slime.

4. Seal the bag, making sure that there is no air in the bag. Any air left in the bag will make it difficult to mix the mixture.

5. Massage the closed bag until the cornstarch and water is completely mixed. You should not see any gaps in color or chunks of cornstarch.

Tips & Warnings

• Keep slime sealed in the resealable zipper bag for future use.

• Slime can stain surfaces and is very messy, so have kids experiment with slime on a covered surface.

• Kids should wash their hands thoroughly after playing with slime.

• Have kids squeeze slime to see how it behaves like a solid. When they let go of the slime, it will drip like a liquid.

• While this mixture isn't harmful, you should tell kids not to eat it.

• Do not dispose of slime down any drain as it will ruin plumbing.

References

• Bizarre Stuff You Can Make in Your Kitchen: The Page That Dripped Slime!
• San Francisco Exploratorium: Outrageous Ooze

Resources

• Knight Foundation Summer Institute: Exploring Properties of Polymers