STRUCTURE  :
HEAD - Molecule have a long chain non polar Hydrocarbon, whose structure can be Studied as follows:-
Head : It is water soluble & ‘-‘Vely charged.
Tail   :   It is oil soluble.

CLEANSING ACTION 

When solution  water is poured over the DIRTY surface  the  hydrocarbon Tail  of the each molecules peg in to it, while the (–ve) HEAD is held in water. The dirt or grease layer is then disloged from the skin by rubbing or from garment by tumbling  and stirring. Each grease globule thus separated in PIN CUSHIONED by hydrocarbon  TAILS with (-ve) HEADS out wards in water. The (-ve) HEAD globules keep apart by mutual repulsions & are said to have emulsified.The emulsified grease globules bearing dirt can be readly washed with water.