The activated complex is the intermediate that is formed between the states of reactants "F" and products "G".
Letter A represents the activation energy of the reaction, that is the difference in potential energy between the reactants "F" and activated complex "B".
Letter C represents the enthalpy change of the reaction, that is the difference in potential energy between products "G" and reactants "F".
Letter D represents the potential energy of products "G".
Letter E represents the potential energy of reactants "E".
