(b) State two methods by which the surface tension of a liquid can be reduced.
(a) Surface tension
Surface tension is the force per unit length acting along (perpendicular to) a line drawn on the surface of a liquid, tending to make the surface behave like a stretched elastic skin and to contract to the smallest possible area. Its unit is the newton per metre (\( \text{N m}^{-1} \)).
(b) Two methods of reducing surface tension
Raising the temperature of the liquid (surface tension falls as temperature rises).
Adding a surface-active substance such as soap, detergent or oil (impurities) to the liquid.
Surface tension is the force per unit length acting along (perpendicular to) a line drawn on the surface of a liquid, tending to make the surface behave like a stretched elastic skin and to contract to the smallest possible area. Its unit is the newton per metre (\( \text{N m}^{-1} \)).
(b) Two methods of reducing surface tension
Raising the temperature of the liquid (surface tension falls as temperature rises).
Adding a surface-active substance such as soap, detergent or oil (impurities) to the liquid.