This results in part of the molecule being positively charged and other areas being negatively charged. Therefore, the electrons will be shared equally. A water molecule is polarized because oxygen has a stronger attraction for the shared electrons than do the hydrogen atoms. Two water molecules will attract each other because the negative charge on the oxygen atom of one water molecule will be pulled toward the positive charge on one of the hydrogen atoms in another water molecule. Hydrogen bonding results from the attraction between two polarized molecules.
Cohesion is the attraction between two or more polarized molecules of the same substance.
Adhesion is the attraction between two or more polarized molecules that are not alike. A catalyst is a substance that affects the rate of a chemical reaction but is not consumed during the reaction. The amount of a catalyst present at the end of a reaction should be same as was present at the beginning of the reaction. An enzyme is a catalyst composed of protein. Many catalysts, such as platinum, are not composed of protein.