Polymer Bouncy Ball Science Lab
Mix borax, cornstarch, and glue to create custom bouncy balls — a hands-on polymer chemistry experiment with a satisfying tactile payoff.
What You'll Need
- 1Borax powder
- 2Cornstarch
- 3White school glue
- 4Food coloring
- 5Warm water
- 6Small cups for mixing
- 7Measuring spoons
What You'll Need
Borax powder
Cornstarch
White school glue
Food coloring
Warm water
Small cups for mixing
Measuring spoons
How to Play
Dissolve 1/2 tablespoon borax in 2 tablespoons warm water.
In a separate cup, mix 1 tablespoon glue, 1/2 tablespoon cornstarch, and food coloring.
Pour the borax solution into the glue mixture and stir for 15 seconds.
When it starts to solidify, pull it out and roll between your palms into a ball.
Keep rolling until smooth and round — this takes about a minute of shaping.
Bounce it on a hard surface. Measure how high it goes.
Make a second ball with different ratios and compare bounce heights.
Tips
Borax cross-links the glue polymers, creating a flexible solid. Real polymer chemistry.
More cornstarch = less bouncy but more moldable. More glue = bouncier but less firm.
These balls dry out within a day or two. Make fresh ones each time.
Keep a lab notebook: record each recipe, coloring, and bounce height for a proper experiment.
Borax is not safe to eat but is fine for handling. Wash hands after the activity.
Frequently Asked Questions
How long does this activity take?
This activity takes about 25 min, with 5 min of preparation time beforehand.
What materials do I need?
You'll need: borax powder, cornstarch, white school glue, food coloring, warm water, and 2 more items.
What age is this activity for?
This activity is designed for 8-12 years. You can adapt it for younger or older children by adjusting the complexity.
Can this be done indoors?
This activity is designed for indoor play, making it perfect for rainy days or when you're staying inside.
How difficult is this activity?
This activity has a moderate difficulty level. It may require some preparation or guidance, but is manageable for most families.
Ratings & Reviews
Sign in to leave a rating or review.
Add to Your Weekly Plan
Schedule this activity into your family's week. It takes about 25 min.
Free account required to save plans
Explore More
Love this activity?
Create a free account and add it to your weekly planner. Discover hundreds more activities matched to your child's age.