The reaction shown by the second diagram is more exothermic. There is a greater difference in energy between the reactants and products. The green arrow is longer.

which helps the reaction proceed more smoothly. This matched their density functional theory (DFT) predictions and was clearly shown in free energy diagrams and 2D volcano plots that link binding ...

Activation energy is the minimum energy needed for ‘successful collisions’ where atoms within the reactants rearrange to form products. It can be represented on an energy level diagram.