Acids, bases, and salts are three classes of compounds that form ions in water solutions. Solutions are homogenous mixtures of two or more substances. Energy is exchanged or transformed in all chemical reactions and physical changes of matter. Energy is released when a material condenses or freezes and absorbed when a material evaporates or melts. Chemical reaction rates depend on factors that influence the frequency of collision of reactant molecules.
Chemical equilibrium is a dynamic process at the molecular level.
Equilibrium is established when forward and reverse reaction rates are equal. The bonding characteristics of carbon lead to the possibility of many different molecules of many sizes, shapes, and chemical properties. This provides the biochemical basis of life.