surface tensionsurface tension
The property of the water in this bowl is an example of surface tension.
Surface tension is a property of liquids where the exposed surface shrinks to the smallest possible area because of unequal forces near the surface.
An example of surface tension is a property of water in a bowl.
a property of liquids in which the exposed surface tends to contract to the smallest possible area because of unequal molecular cohesive forces near the surface: measured by the force per unit of length
- A property of liquids arising from unbalanced molecular cohesive forces at or near the surface, as a result of which the surface tends to contract and has properties resembling those of a stretched elastic membrane.
- A measure of this property.
A property of liquids such that their surfaces behave like a thin, elastic film. Surface tension is an effect of intermolecular attraction, in which molecules at or near the surface undergo a net attraction to the rest of the fluid, while molecules not near the surface are attracted to other molecules equally in all directions and undergo no net attraction. Because of surface tension, the surface of a liquid can support light objects (such as water beetles on the surface of a pond). Surface tension is responsible for the spherical shape of drops of liquid; spheres minimize the surface area of the drop and thus minimize surface tension.
See also capillary action
- The early writers on capillary action supposed that the diminution of capillary action was due simply to the change of density corresponding to the rise of temperature, and, therefore, assuming the surface-tension to vary as the square of the (37)?(f) =eP f (38) density, they deduced its variations from the observed dilatation of the liquid by heat.
- Relation Of Surface-Tension To Temperature It appears from the experiments of Brunner and of Wolf on the ascent of water in tubes that at the temperature t° centigrade T =75.20 (I -0.00187t) (Brunner); =76 08 (i-o o02t-Po ooOo0415t 2), for a tube .02346cm.diameter (Wolf); = 77.34(1 -o oo181t), for a tube 03098 cm.
- If the denser body be solid we can often demonstrate this; for the liquid tends to spread itself over the surface of the solid, so as to increase the area of the surface of contact, even although in so doing it is obliged to increase the free surface in opposition to the surface-tension.
- Although throughout a certain range the surface-tension varies rapidly with the degree of contamination, it is remarkable that, as was first fully indicated by Miss Pockels,the earlier stages of contamination have little or no effect upon surface-tension.
- But when the surface-tension of A exceeds the sum of the tensions of the surfaces of contact of B with air and with A, it is impossible to construct the triangle of forces, so that equilibrium becomes impossible.