Get smart curated videos delivered to your inbox every week.      
The Kid Should See This

Seven surface tension experiments – Physics Girl

This Physics Girl video highlights seven different surface tension experiments that you can easily try at home or in the classroom. Have any of these around? A plate, a glass, a penny, an index card, a paperclip, an eye dropper, a cup of coffee, dish soap, or some food coloring… and if you’re teaming up with an adult, get a pan and stove, too.

Surface tension is the energy, or work, required to increase the surface area of a liquid due to intermolecular forces. Since these intermolecular forces vary depending on the nature of the liquid (e.g. water vs. gasoline) or solutes in the liquid (e.g. surfactants like detergent), each solution exhibits differing surface tension properties.

Test those properties with a few experiments we’ve enjoyed before — milk fireworks and soap boat — and lots of experiments that we’ve never tried: Surface spheres, floating card, suddenly sinking paperclip, penny dropper, and the Leidenfrost Effect.

Next: Check out more of our favorite Physics Girl vids: The Stacked Ball Drop, How to make a Crazy Pool Vortex, and The Physics Behind a Curveball.

This Webby award-winning video collection exists to help teachers, librarians, and families spark kid wonder and curiosity. TKSST features smarter, more meaningful content than what's usually served up by YouTube's algorithms, and amplifies the creators who make that content.

Curated, kid-friendly, independently-published. Support this mission by becoming a sustaining member today.

🌈 Watch these videos next...

Nature’s Scuba Divers – How Beetles Breathe Underwater

Rion Nakaya

“Plain old soap and water absolutely annihilate coronavirus.” – Vox

Rion Nakaya

The Stacked Ball Drop (and Supernovas) – Physics Girl

Rion Nakaya

Which is better: Soap or hand sanitizer?

Rion Nakaya

Flottille: Unfolding micro-origami by Etienne Cliquet

Rion Nakaya

Odyssey: A universe of ink, oil, soap, and glitter in macro detail

Rion Nakaya

Demo of the FloWave Ocean Simulator

Rion Nakaya

How do your eyes perceive color?

Rion Nakaya

Ferrofluid + Glow Sticks – The Physics Girl

Rion Nakaya