To find how many valence electrons are in an element, simply locate the column number that it is in, and that determines the number of valence electrons in an element.
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".
