User talk:Theboyof1990

SURFACE TENSION' Surface tension is caused by the inward attraction of molecules at a boundary. This attraction produces curvature of free liquid surfaces, and causes a pressure difference to exist at the curved boundary: Δp = γ(1/R1 + 1/R2), where Δp = pressure difference, R1 and R2 = principal radii of curvature. γ, the surface tension at a liquid–gas boundary, is usually measured in mN m-1. At liquid–liquid boundaries there is interfacial tension; at liquid–solid boundaries adhesion tension. Surface tension is an attractive property of the surface of a liquid. It is what causes the surface of a portion of liquid to be attracted to another surface, such as that of another portion of liquid (as in connecting bits of water or of mercury).

Surface tension causes many liquids to behave as an elastic sheet and allows insects, such as the water strider (pond skater, UK), to walk on water. It allows small objects, even metal ones such as needles, razor blades, or foil fragments, to float on the surface of water, and it is the cause of capillary action. Everyday observations of surface tension include the formation of water droplets on various surfaces and the concavity of the surface of water in a glass. In the former example, water sticks better to itself than to a particular surface, thus allowing it to form droplets. And, in the later example, water sticks strongly to the side of a glass, overcoming the downward force of gravity that causes the center of the surface to curve downward.

The physical and chemical behavior of liquids cannot be understood without taking surface tension into account. It governs the shape that small masses of liquid can assume and the degree of contact a liquid can make with another substance.

Applying Newtonian physics to the forces that arise due to surface tension accurately predicts many liquid behaviors that are so commonplace that most people take them for granted. Applying thermodynamics to those same forces further predicts other more subtle liquid behaviors.

Surface tension has the dimension of force per unit length, or of energy per unit area. The two are equivalent — but when referring to energy per unit of area people use the term surface energy — which is a more general term in the sense that it applies also to solids and not just liquids. SOME EFFECTS OF SURFACE TENSION

Breakup of a moving sheet of water bouncing off of a spoon.

Photo of flowing water adhering to a hand. Surface tension creates the sheet of water between the flow and the hand.

A soap bubble balances surface tension forces against internal pneumatic pressure.

Surface tension prevents a coin from sinking: the coin is indisputably denser than water, so it cannot be floating due to buoyancy alone.

A daisy. The entirety of the flower lies below the level of the (undisturbed) free surface. The water rises smoothly around its edge. Surface tension prevents the water from submerging the flower.

Photo showing the "tears of wine" phenomenon, which is induced by a combination of surface tension modification of water by ethanol together with ethanol evaporating faster than water.

Fresh morning dew on a Water Horsetail (Equisetum fluviatile) ‘ “ ’ ”COJFT?....