Surface tension

Definition

Surface tension is the cohesive force at the surface of a liquid that makes it behave as an elastic sheet. It results from the greater attraction of liquid molecules to each other than to the molecules in the air.

5 Must Know Facts For Your Next Test

1. Surface tension is measured in force per unit length (N/m).
2. It is caused by cohesive forces between liquid molecules.
3. Surface tension allows small objects, even those denser than water, to float on its surface without sinking.
4. Temperature affects surface tension; higher temperatures generally decrease it.
5. Surfactants can reduce surface tension by disrupting molecular interactions at the surface.

Review Questions

Related terms

Cohesion:

The force of attraction between similar molecules within a substance, such as water molecules.

Adhesion:

The force of attraction between different kinds of molecules, such as water and glass.

Capillary Action:

The ability of a liquid to flow in narrow spaces without the assistance of external forces like gravity, often occurring due to adhesion and cohesion.