A potential energy diagram is shown. A graph is plotted with Potential Energy in KJ on the y axis and Reaction Pathway on the x axis. The graph starts at 30 on the y axis and it is initially horizontal, labeled Reactants, and then rises up as a smooth curve and reaches its peak when y is 65 kilojoules. The curve comes down until y is 55 kilojoules where it becomes horizontal again, and it is labeled Products. What is the activation energy of this reaction? 10 kJ 25 kJ 30 kJ 35 kJ