S

Surface Tension

γ = F/L; γ(water, 20°C) ≈ 72.8 mN/m
Quick Reference
Formula / Notationγ = F/L; γ(water, 20°C) ≈ 72.8 mN/m
Also Known AsInterfacial tension, capillary pressure, γ (gamma)

What is Surface Tension?

The tendency of liquid surfaces to contract and resist rupture, caused by cohesive forces between surface molecules. Surface tension allows insects to walk on water and causes capillary action. It decreases with increasing temperature and is reduced by surfactants (detergents).

Formula & Notation

γ = F/L; γ(water, 20°C) ≈ 72.8 mN/m

Other Names / Synonyms: Interfacial tension, capillary pressure, γ (gamma)

Properties & Characteristics

Surface tension is the property of a liquid surface that causes it to behave like an elastic membrane due to cohesive forces between surface molecules. It arises because molecules at the surface have fewer neighbouring molecules and thus higher potential energy than interior molecules. Surface tension is measured as force per unit length (N/m) or energy per unit area (J/m²). It decreases with increasing temperature.

Uses & Applications

Surface tension drives capillary action used in chromatography and biological fluid transport. Detergents (surfactants) reduce water's surface tension to improve cleaning. Lung surfactant reduces surface tension in alveoli to prevent collapse during breathing.

Safety Information

Substances that reduce surface tension (surfactants) can enhance penetration of other chemicals through skin and biological membranes. Some surfactants are irritating to skin and eyes.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Surface Tension
Formula γ = F/L; γ(water, 20°C) ≈ 72.8 mN/m
Synonyms Interfacial tension, capillary pressure, γ (gamma)

Frequently Asked Questions

The tendency of liquid surfaces to contract and resist rupture, caused by cohesive forces between surface molecules. Surface tension allows insects to walk on water and causes capillary action. It decreases with increasing temperature and is reduced by surfactants (detergents).

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