The soap molecule has a nonpolar and a polar when it is dissolved in water. when it dissolves in water, the sodium stearate congregates to form small spheres (called micelles) with the on the inside and the on the surface. the interacts with the polar water molecules, while the can attract and interact with the nonpolar grease. this allows the soapy water to remove the grease by trapping the grease inside the micelle.