individual particles may extremely differ for example if an ambient temperature in a room is 25 u00b0 c then the energy distribution function has an average value u201c e av u201d of 25 u00b0 c but there are also particles with the energies corresponding to u2212 100 u00b0 c or u2212 200 u00b0 c a smaller percentage as well as 100 u00b0 c 200 u00b0 c 1000 u00b0 c the descending right side of the curve the magnitude of the activation energy e shown in fig1 as a horizontal line at y e is shown in fig2 as the vertical line x e only particles with energy contents of e or higher can react corresponding to the shaded areas to the right of e in the curves of fig2 if throughout the volume of the reagent the reagent does not have an average energy above e then the reaction should not be considered completely impossible rather the reaction may take place for extremely energetic molecules corresponding to particles in the shaded area of the curve u201c tail u201d but at very slow rate for example oxidation below flash temperature as the particles belonging to the shaded area start to react new ones will come to take their place due to the energy redistribution but this process requires time the rate of this redistribution governs the reaction rate it is important to keep in mind that all the reactions are recoverable i e if there are the particles with energy e or higher which can overcome the energy barrier from left to right then the.