Surface tension can be broken by introducing substances that weaken the cohesive forces between liquid molecules at the surface, effectively "snapping" it like a balloon.
The video provided showcases a demonstration using soap and pepper. Here's a breakdown of how it works:
- Initial State: Water molecules on the surface are tightly bound to each other, creating surface tension. The pepper flakes float on top due to this tension.
- Introduction of Soap: Soap is a surfactant, meaning it reduces surface tension. When soap is introduced, it disrupts the cohesive forces between water molecules.
- The Break: The soap molecules insert themselves between the water molecules, decreasing the attraction between them. The surface tension is weakened or "broken."
- Observed Effect: Because the surface tension is reduced where the soap is introduced, the higher surface tension of the surrounding water pulls the pepper away from the soap, creating the observed effect of the pepper flying to the edge of the plate.
In essence, surface tension breaks when the forces holding the liquid surface together are weakened by external factors such as surfactants like soap.
