91. How does detergent and soap works ?
Soaps and detergents are made from long molecules that contain a head and tail. These molecules are called surfactants. Water alone can't clean clothes because it won't attach to molecules of grease and dirt. Detergent is different. The surfactants it contains are made of molecules that have two different ends. One end is strongly attracted to water; the other is attracted to oily substances like grease.