Slime:
Cornstarch and Water.
MESSY?? You bet.
FUN?? Absolutely
1. Pour 2 cups of corn starch into a large bowl.
Tip:
It is difficult to give an exact recipe for making cornstarch slime because humidity can be a factor. So, I have suggested that you start with a 2:1 ratio of corn starch to water.
2. Start with 1 cup of tap water. Slowly add the water as you mix the mixture with your hands. You want all of the cornstarch wet.
Tip:
A good mixture will be very difficult to stir with a spoon, but if you hold some of the slime in your hands, it will ooze between your fingers.
Slap the surface of the mixture and it will feel as if you slapped a solid surface, so don’t slap hard.
Troubleshooting Tips:
The slime feels dry–add drops of water to the mixture and thoroughly mix. It will not take much for the mixture to change so do add the water a drop at a time
The slime feels too wet–sprinkle a small amount of corn starch on the surface of the mixture and work it in with your hands. As with the water–add small amounts and mix before adding more.
What’s Happening and Why:
Corn Starch Slime is a dilatant, which is any substance that thickens under stress (stirred, hit, or quickly pushed or pulled on).
When the cornstarch slime is stressed it thickens because the water is squeezed out from between the starch molecules. With the cornstarch molecules close together, the mixture behaves like a solid.