Question

What is Surface Tension?

Answer

Surface Tension - Each molecule (or atom) of liquid attracts the neighbouring molecule with the same force (called cohesive force). However, as every molecules is gathered by a number of molecules in every direction, the net effect on the molecule is zero (figure). If we draw an imaginary line of a length on the surface of the liquid, the net value of force acting on this line per unit length is called surface tension. Surface tension, S = Force/Length (S = F/L)