Surface Tension

Surface Tension

• Surface tension is a property of liquids.
• It describes the tendency of a liquid's surface to resist external forces and minimize its surface area.
• This resistance is due to the cohesive forces between liquid molecules.

Floating Objects

• Objects with higher densities than water can float on its surface due to surface tension.
• This happens because the surface tension of the water creates a thin, elastic-like skin that can support the weight of the object.
• This effect is more pronounced for smaller objects.

Liquid-Air Interface

• Surface tension at the liquid-air interface is caused by the imbalance of intermolecular forces.
• Liquid molecules inside the bulk of the liquid experience attractive forces from all directions.
• Molecules at the surface experience a net inward force due to the lack of attraction from above the surface.
• This imbalance creates a strong surface layer, resistant to disruption.

Surface Tension Effect

• The net effect of surface tension is to minimize the liquid's surface area.
• The cohesive force between the molecules creates a tight surface layer, reducing the area.

Secondary Mechanism

• The second primary mechanism contributing to surface tension is the attraction between liquid molecules and those of the surrounding medium.
• These forces, called adhesive forces, can be stronger than cohesive forces, causing the liquid to spread across the surface.
• This is why water, with stronger adhesive forces to glass than cohesive forces, wets a glass surface.

Test your knowledge of surface tension with this quiz! Discover how this fascinating property of liquids affects the behavior of various objects and learn about the science behind it.