- Soap molecules are surfactants, possessing a dual nature: a hydrophilic (water-attracting) head and a hydrophobic (oil-attracting) tail. - In water, these molecules aggregate to form micelles, which are spherical structures where the hydrophobic tails point inward, away from the water, forming a non- polar core. The hydrophilic heads face outward towards the water. - When soap is added to water containing oil or grease (which are non-polar), the hydrophobic tails of the soap molecules dissolve in the oil/grease droplets. - These oil/grease droplets become surrounded by soap molecules with their hydrophilic heads facing the water, forming an emulsion. The oil/grease is effectively trapped within the hydrophobic core of these new micelles. - Because the outer surface of these micelles is hydrophilic, they become soluble or easily suspended in water and can be rinsed away, carrying the dirt (oil/grease) with them.