UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
How it Works
Ask a Question
Search Topics
Our Scientists
Science Links
Contact Information
What is surface tension and what makes it increase or decrease?
Question Date: 2012-01-12
Answer 1:

Surface tension is a result of a substance holding together with itself, so you would imagine that a substance with strong intermolecular forces (like water) would have a high surface tension. These molecules at the surface form a layer and you need a certain amount of energy to overcome and break the surface layer. When you heat something up, it adds energy, and that energy can overcome the surface tension.

You can also add things to the substance to interfere or disrupt its intermolecular forces. For example, water has a high surface tension because it is strongly attracted to itself. However, if you add alcohol, instead of water interacting only with other water molecules, it now interacts (less strongly) with alcohol, and the surface tension of the mixture will be lower.

Answer 2:

Surface tension is the property of liquids that allows them to resist external forces. It is caused by attractive interactions between molecules at the surface of the liquid. The strength of these cohesive molecular interactions dictates the amount of surface tension for a given liquid.

Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2017 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use