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.
- 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.
- 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.
- This drop will not spread out like the first drop, but will take the form of a flat lens with a distinct circular edge, showing that the surface-tension of what is still apparently pure water is now less than the sum of the tensions of the surfaces separating oil from air and water.
- 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.
- In the next place, there is the surface-tension acting downwards, but at an angle a with the vertical, across the circular section of the bubble itself, whose circumference is 21ry, and the downward force is therefore 2lryT cos a.