Video paused
Surface Tension Experiment
Watch Video Tutorial
Science & Discovery Projects6-12 years
Easy
5 Minutes
LIVE
Loading...Surface Tension Experiment
Bilal Şentürk
Maker
What You'll Need
- Large clear square plastic container
- 500 ml water
- 10 g black pepper
- 10 g thyme
- 10 ml liquid dish soap
- A toothpick (or a clean fingertip)
Surface Tension Experiment
Get all the materials you need for this project in one package!
Includes:
Large clear square plastic container
500 ml water
10 g black pepper
10 g thyme
10 ml liquid dish soap
A toothpick (or a clean fingertip)All materials in one package!
0.0/5(0 reviews)Verified reviews
Free Shipping✓
Fast delivery5 days
Return guarantee30 days
In stock
Limited offer!
SSL
Visa/MC
Secure
Let's Make It! Step-by-Step Guide
- Fill your bowl almost to the rim with still, clean water.
- Invite your child to observe how smooth and mirror-like the surface looks.
The Science Behind It
Water molecules at the surface cling tightly to each other, forming a tension-filled “skin” that can support small, light objects. This phenomenon is called surface tension. When you introduce soap, its molecules wedge between the water molecules, weakening their bonds and collapsing the surface film. As the “skin” breaks, the floating pepper flakes lose their support and race toward the stronger tension at the bowl’s perimeter.
Helpful Tips
- Touch the soap only to the very center of the surface for the most dramatic effect.
- Try different soap brands or concentrations to see which breaks tension fastest.
- Use a clear bowl on a dark background to make the pepper movement easier to see.
- After the experiment, rinse the bowl with warm water to remove all soap residue.
Try These Variations!
- 1Alternative Powders: Float colored spices (turmeric, paprika) for a rainbow effect.
- 2Two-Point Release: Touch soap at two spots simultaneously and watch the pepper split in both directions.
- 3Temperature Test: Repeat with hot vs. cold water to see how temperature affects surface tension.
- 4Vinegar & Oil: Compare the effect of dish soap to vinegar or cooking oil on the pepper’s behavior.