When it come to busting up grease and dirt, few things work better than soap, thanks to the amazing structure of soap molecules! These molecules work by having two very different sides. One side is an oxygen (O) ion loosely hanging on to a sodium (Na) or potassium (K) ion. An ion is an electrically charged atom or group of atoms. Because this end is very similar to water molecules (H2O) it can mix well with water. The other end is a long chain of carbon and hydrocarbon (H) atoms linked together.