Detergents clean surfaces on the principle of surface tension. Surface tension is the tendency of a liquid surface to contract into the smallest possible area. This is due to the cohesive forces between the molecules of the liquid. When a detergent is added to water, it lowers the surface tension of the water. This allows the detergent molecules to more easily penetrate the surface of the dirt or grime, and to lift it away from the surface. The detergent molecules also surround the dirt particles, which prevents them from re-adhering to the surface.
Viscosity is a measure of a fluid’s resistance to flow. A fluid with high viscosity is thick and slow-moving, while a fluid with low viscosity is thin and easily flows. Detergents do not affect the viscosity of water.
Elasticity is the ability of a material to return to its original shape after being deformed. Detergents do not affect the elasticity of water.
Floatation is the ability of an object to float on a liquid. Detergents do not affect the floatation of objects.