SURFACE
TENSION This is the property of a liquid, which makes it behave as if it contains an
elastic skin at its surface.
When a
light pin is gently placed on a
liquid surface, its light weight subjects the
SURFACE molecules of the liquid to a state of tension. The surface molecules tend to stretch out with slight depression of the liquid surface, hence, surface tension.
Molecular explanation of surface tension; if a molecule “A” is fully into a liquid. It will be acted upon equally on all sides by the molecules of the liquid. Hence molecule A is in a state of equilibrium but molecule B at the surface of the liquid is acted upon by more molecules of the liquid than molecules of the air. There is therefore a resultant inward force, which subjects the surface molecules of the liquid to a state of tension. Hence surface tension.
Surface tension can also be seen as the ration of the force parallel to a liquid surface per unit length. Surface tension is equal to force divided by length.
EFFECTS OF SURFACE TENSION
A drop of water from a top appears spherical because of surface tension.
Light insects like mosquito perch on water surface without sinking
Light insects like mosquito perch on water surface without sinking
Light objects like razor blade or pin rest on water surface because of surface tension. Water does not sink into an umbrella or raincoat or converse because of surface tension.
METHODS OF REDUCING SURFACE TENSION
By increase temperature (boiling) which will increase the kinetic energy
By Adding detergent or soap
By Addition of impurities like camphor
ELASTICITY
This is the process where by a substance increases or decrease in size when a force is
applied to it, but regains the original size when the applied force is removed.
ELASTIC MATERIAL
These are materials which increase or decrease in size wen a force is applied but regains the original size when the applied free is removed
HOOKS LAW
This state that the extension produced by an elastic material is directly proportional to the applied force or load provided that elastic limit is not exceeded.
ELASTIC LIMITThis is the point beyond which extension is no longer directly proportional to load
More abstracts about the Surface tension and Elasticity